Tone generating device and method using a time stretch/compression control technique

• US 6,169,240 B1
• Filed: 01/27/1998
• Issued: 01/02/2001
• Est. Priority Date: 01/31/1997
• Status: Expired due to Term

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Suzuki, Hideo
• Primary Examiner(s): Donels, Jeffrey
• Application Number:
  US09/014,417
• Time in Patent Office: 1,071 Days
• Field of Search: 846/04, 846/05, 846/29, 704/503
• US Class Current: 84/605
• CPC Class Codes: G10H 7/008 Means for controlling the transition from one tone waveform to another
• CPC Class Codes: G10H 7/02 in which amplitudes at successive sample points of a tone waveform are stored in one or more memories

Abstract

A pitch of a tone to be generated is designated, and simultaneously control information to be used for time-axis stretch/compression control is generated. Discrete locations of waveform data to be read out from memory are designated with the time axis of the waveform data controlled to be stretched or compressed in accordance with the control information, and part of the waveform data at the designated locations are read out at a rate corresponding to the designated pitch. For example, virtual read addresses corresponding to the control information and actual read addresses corresponding to the designated pitch are generated, and the actual read addresses are controlled, at the individual discrete locations, to follow the virtual addresses. Thus, the rate at which the waveform data are read out from the memory is variably controlled to generate a desired pitch, during which time the waveform memory can be optionally controlled to be stretched or compressed along the time axis independently of the readout rate or pitch control. By applying the time-axis stretch/compression control to various performance styles, real-time control, modulation control or tone-generating-time control, it is possible to significantly enhance expression and controllability of the generated tone.

Claims

1. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a control information generating section that generates control information specifying, in a time function, an address location of the waveform data to be read out from said waveform memory;

an address generating section that generates a read address advancing at a rate corresponding to the pitch designated by said pitch designating section;

a control unit that makes a comparison between the address location specified by the control information and a location of the read address generated by said address generating section and controls shifting of the read address in accordance with a result of the comparison; and

a section that reads out the waveform data on the basis of the read address controlled by said control unit.

2. A tone generating device as recited in claim 1 wherein the waveform data stored in the waveform memory are divided into a plurality of data divisions and managed in such a manner that respective first waveform data of the data divisions have substantially the same amplitude and substantially the same slope, and

wherein when a difference between the address location specified by the control information and the location of the read address generated by said address generating section has exceeded a predetermined value, said control unit shifts the read address by an amount corresponding to one or more of the data divisions.

3. A tone generating device as recited in claim 1 which further comprises a cross-fading section that, when a shift of the read address is to be carried out by said control unit, performs cross-fade synthesis between the waveform read out from said waveform memory on the basis of the read address generated before the shift and the waveform read out from said waveform memory on the basis of the read address generated after the shift.

4. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform having a modulation effect imparted thereto;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information to control a time axis of modulation;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

5. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information in correspondence with a predetermined portion of the waveform data to be repetitively read out from said waveform memory;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out the waveform data from said waveform memory at a rate corresponding to the pitch designated by said pitch designating section, wherein when the predetermined portion is to be read out repetitively, said readout section reads out the waveform data at the locations designated by said control unit at the rate corresponding to the designated pitch.

6. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information varying with time;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

7. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform having a tonal characteristic variation imparted thereto over a predetermined period based a predetermined style of performance;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information to control a tone generating period based on the predetermined style of performance;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

8. A tone generating device as recited in claim 7 wherein the tonal characteristic variation imparted to the waveform data are a variation of at least one of tone pitch, color and volume.

9. A tone generating device as recited in claim 7 wherein said control information designates either or both of start and end points of the tone generating period based on the predetermined style of performance, and a time length of the variation.

10. A tone generating device as recited in claim 7 wherein said control information designates one of start and end points of the tone generating period based on the predetermined style of performance, and a rate of the variation.

11. A tone generating device comprising:

a waveform memory having stored therein first waveform data representative of a first waveform, second waveform data representative of a second waveform, and third waveform data of a plural-cycle third waveform having a tonal characteristic variation imparted thereto to interconnect said first waveform and said second waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that, when a transfer from said first waveform to said second waveform is instructed, performs control such that said first waveform and said second waveform are read out with said third waveform inserted therebetween;

a section that generates control information to control a time over which said third waveform is to be used;

a control unit that designates, in response to passage of time, discrete locations of at least part of said third waveform to be read out from said waveform memory with a time axis of said third waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out the waveform data from said waveform memory at a rate corresponding to the pitch designated by said pitch designating section, wherein when said third waveform data are to be read out, said readout section reads out said third waveform data at the locations designated by said control unit at the rate corresponding to the designated pitch.

12. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information in correspondence with a predetermined partial tone generating period;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

13. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a color designating section that designates a color of the tone to be generated;

a section that generates control information varying in a manner corresponding to the color designated by said color designating section, in response to passage of time from a tone-generation starting point;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory plural cycles of the waveform data corresponding to the designated color at a rate corresponding to the pitch designated by said pitch designating section, wherein said readout section reads out the waveform data at the locations designated by said control unit at the rate corresponding to the designated pitch,

wherein the waveform data of a plural-cycle waveform stored in said waveform memory is shared for at least two different colors and the control information for the at least two different colors is arranged in different manners.

14. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information in real time during generation of a tone;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

15. A tone generating device comprising:

a waveform memory having stored therein plural different sets of waveform data of plural-cycle waveforms;

a pitch designating section that designates a pitch of a tone to be generated;

a waveform designating section that designates any one of the sets of waveform data, said waveform designating section sequentially switching the designated set to another one of the sets in response to passage of time;

a section that generates control information;

a control unit that designates, in response to passage of time, discrete locations of the set of waveform data, designated by said waveform designating section, to be read out from said waveform memory with a time axis of the set of waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

16. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a section that generates control information to control a time length over which a tone is to be generated;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed in accordance with the control information; and

a readout section that reads out from said waveform memory the waveform data at the locations designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section.

17. A method of generating a tone on the basis of readout from a waveform memory having stored therein waveform data of a plural-cycle waveform, said method comprising:

a step of designating a pitch of a tone to be generated;

a step of generating control information specifying, in a time function, an address location of the waveform data to be read out from said waveform memory;

a step of generating a read address advancing at a rate corresponding to the pitch designated by said step of designating a pitch;

a step of making a comparison between the address location specified by the control information and a location of the read address generated by said step of generating a read address and controlling shifting of the read address in accordance with a result of the comparison; and

a step of reading out the waveform data on the basis of the read address controlled by said step of controlling.

18. A method as recited in claim 17 wherein the waveform data stored in the waveform memory are divided into a plurality of data divisions and managed in such a manner that respective leading waveform data of the data divisions have substantially the same amplitude and substantially the same slope, and

wherein when a difference between the address location specified by the control information and the location of the read address has exceeded a predetermined value, said control step shifts the read address by an amount corresponding to one or more of the data divisions.

19. A method as recited in claim 17 which further comprises a step of, when a shift of the read address is to be carried out by said shift step, performing cross-fade synthesis between the waveform read out from said waveform memory on the basis of the read address generated before the shift and the waveform read out from said waveform memory on the basis of the read address generated after the shift.

20. A method of generating a tone on the basis of readout from a waveform memory having stored therein waveform data of a plural-cycle waveform, said method comprising:

a step of designating a pitch of a tone to be generated;

a step of generating control information;

a control step of designating, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control step, to be stretched or compressed in accordance with the control information; and

a step of reading out from said waveform memory the waveform data at the locations designated by said control step at a rate corresponding to the pitch designated by said step of designating,

whereby a tone is generated which has the designated pitch and waveform data of a characteristic controlled, by said control step, to be stretched or compressed along a time axis in accordance with the control information.

21. A machine-readable storage medium containing a group of instructions for causing said machine to perform a method for generating a tone on the basis of readout from a waveform memory having stored therein waveform data of a plural-cycle waveform, said method comprising the steps of:

designating a pitch of a tone to be generated;

generating control information specifying, in a time function, an address location of the waveform data to be read out from said waveform memory;

generating a read address advancing at a rate corresponding to the pitch designated by said step of designating a pitch;

comparing the address location specified by the control information with a location of the read address generated by said step of generating a read address;

controlling a shifting of the read address in accordance with a result of the step of comparing; and

reading out the waveform data from said waveform memory on the basis of the read address controlled by said step of controlling a shifting.

22. A machine-readable storage medium containing a group of instructions for causing said machine to perform a method for generating a tone on the basis of readout from a waveform memory having stored therein waveform data of a plural-cycle waveform, said method comprising the steps of:

designating a pitch of a tone to be generated;

generating control information corresponding to a stretching or a compression of the waveform;

designating, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory at a point along the time axis determined by said control information; and

reading out from said waveform memory the waveform data at the locations designated by said step of designating discrete locations at a rate corresponding to the pitch designated by said step of designating a pitch of a tone.

23. A tone generating device comprising:

a waveform generating section that generates waveform data in two channels;

a waveform designating section that designates waveform data to be generated in a first one of said two channels of said waveform generating section and waveform data to be generated in a second one of said two channels of said waveform generating section;

a cross-fade synthesis section that executes cross-fade synthesis such that a transfer occurs from the waveform data generated in said first channel to the waveform data generated in said second channel;

a first control section that sequentially instructs said waveform generating section to generate additional waveform data having an optional length and controls said cross-fade synthesis section to execute the cross-fade synthesis for a period corresponding to the length of the additional waveform data; and

a second control section that after completion of the cross-fade synthesis by said cross-fade synthesis section, controls designation by said waveform designating section in such a manner that the waveform data having been so far generated in said second channel are generated in said first channel and said additional waveform data are generated in said second channel.

24. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a waveform designating section that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled to be stretched or compressed, so as to identify first waveform data at currently designated locations and second waveform data at following locations having been controlled to be stretched or compressed relative to the currently designated locations;

a readout section that reads out, from said waveform memory, said first and second waveform data designated by said waveform designating section, to output said first and second waveform data through first and second channels, respectively;

a cross-fade synthesis section that always executes cross-fade synthesis such that a transfer occurs from said first waveform data supplied through said first channel to said second waveform data supplied through said second channel; and

a control unit that after completion of the cross-fade synthesis by said cross-fade synthesis section, controls designation by said waveform designating section in such a manner that the waveform data having been so far generated in said second channel are outputted by said readout section through said first channel and the waveform data at new locations having been controlled to be stretched or compressed relative to the locations of said second waveform data are outputted by said readout section through said second channel.

25. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a waveform designating section that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled to be stretched or compressed, so as to identify first waveform data at current locations and second waveform data at following locations having been controlled to be stretched or compressed relative to said first waveform data;

a readout section that reads out, from said waveform memory, said first and second waveform data designated by said waveform designating section, to output said first and second waveform data through first and second channels, respectively;

a cross-fade synthesis section that executes cross-fade synthesis such that a transfer occurs from one of said first and second waveform data supplied through one of said first and second channels to another of said first and second waveform data; and

a control unit that after completion of the cross-fade synthesis by said cross-fade synthesis section, controls designation by said waveform designating section in such a manner that said second waveform data continue to be outputted by said readout section through a same one of said first and second channels as having been so far used and the waveform data at new locations having been controlled to be stretched or compressed relative to the locations of said second waveform data are outputted by said readout section through another of said first and second channels and also changes a cross-fading direction in said cross-fade synthesis section.

26. A tone generating device comprising:

a waveform memory having stored therein waveform data of a plural-cycle waveform;

a pitch designating section that designates a pitch of a tone to be generated;

a control unit that designates, in response to passage of time, discrete locations of the waveform data to be read out from said waveform memory with a time axis of the waveform data controlled, by said control unit, to be stretched or compressed;

a waveform designating section that, in response to designation by said control unit, designates a first part of the waveform data at current locations and a second part of the waveform data at locations following the current locations when stretch of the waveform data is to be executed, designates the first part of the waveform data at current locations and a second part of the waveform data at locations preceding the current locations when compression of the waveform data is to be executed, and designates a same part of the waveform data at current locations as first and second part of the waveform data when neither stretch nor compression is to be executed;

a readout section that reads out from said waveform memory said first and second part of the waveform data designated by said control unit at a rate corresponding to the pitch designated by said pitch designating section; and

a cross-fade synthesis section that executes cross-fade synthesis such that a transfer occurs from said first part of the waveform data to said second part of the waveform data.

27. A waveform data cross-fading method comprising:

a step of generating a plurality of cycles of first waveform data;

a step of, at predetermined timing, starting generation of second waveform data that has a same phase as said first waveform data generated at said predetermined timing;

a step of generating a first coefficient decreasing from an initial value of one to a final value of zero over a predetermined period and simultaneously generating a second coefficient increasing from an initial value of zero to a final value of one over said predetermined period; and

a step of controlling a length of said predetermined period to conform to a one-cycle length of said second waveform data.

28. A waveform reproducing device comprising:

a waveform memory having stored therein waveform data of a plurality of waveform portions;

a tone-generation instructing section that instructs generation of a tone and designates a pitch of the tone;

a section that generates control data to control an advance of readout locations of the waveform portions;

an address generating section that generates read addresses advancing at a rate corresponding to the pitch designated by said tone-generation instructing section;

a readout section that reads out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

a control unit that makes a comparison between an advance of the readout locations designated on the basis of the control data and an advance of locations of the read addresses generated by said address generating section and selects, on the basis of a result of the comparison, addresses of a specific one of the waveform portions to be next read out, so as to perform control such that said address generating section starts generating the selected addresses of the specific waveform portion at a point where a phase of the waveform data read out on the basis of the read addresses coincides with a phase of the waveform data designated by the selected addresses; and

a section that reproduces a waveform on the basis of the waveform data read out by said readout section.

29. A waveform reproducing device as recited in claim 28 wherein one of the waveform portions selected at one time and another of the waveform portions selected next time are interconnected by cross-fade.

30. A waveform reproducing device comprising:

a waveform memory having stored therein waveform data of a plurality of waveform portions;

a tone-generation instructing section that instructs generation of a tone and designates a pitch of the tone;

a section that generates time-varying control data to control an advance of readout locations of the waveform portions;

an address generating section that generates read addresses advancing at a rate corresponding to the pitch designated by said tone-generation instructing section;

a readout section that reads out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

a control unit that, for each predetermined reproduction period, makes a comparison between an advance of virtual waveform portion locations designated on the basis of the control data and an advance of waveform portion locations designated by the read addresses generated by said address generating section and selects, on the basis of a result of the comparison, a specific one of the waveform portions to be next read out, so as to perform control such that said address generating section starts generating addresses of the specific waveform portion in a next reproduction period; and

a section that reproduces a waveform on the basis of the waveform data read out by said readout section.

31. A waveform reproducing device as recited in claim 30 wherein one of the waveform portions selected at one time and another of the waveform portions selected next time are interconnected by cross-fade.

32. A method of reproducing a waveform using a waveform memory having stored therein waveform data of a plurality of waveform portions, said method comprising:

a tone-generation instructing step of instructing generation of a tone and designating a pitch of the tone;

a step of generating control data to control an advance of readout locations of the waveform portions;

an address generating step of generating read addresses advancing at a rate corresponding to the pitch designated by said tone-generation instructing step;

a readout step of reading out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

a control step of making a comparison between an advance of the readout locations designated on the basis of the control data and an advance of locations of the read addresses generated by said address generating step and selects, on the basis of a result of the comparison, addresses of a specific one of the waveform portions to be next read out, so as to perform control such that said address generating step starts generating the selected addresses of the specific waveform portion at a point where a phase of the waveform data read out on the basis of the read addresses coincides with a phase of the waveform data designated by the selected addresses; and

a step of reproducing a waveform on the basis of the waveform data read out by said readout step.

33. A machine-readable storage medium containing a group of instructions for causing said machine to perform a method for reproducing a waveform using a waveform memory having stored therein waveform data of a plurality of waveform portions, said method comprising the steps of:

instructing generation of a tone;

designating a pitch of the tone;

generating control data to control an advance of readout locations of the waveform portions;

generating read addresses advancing at a rate corresponding to the pitch designated by said step of instructing generation of a tone;

reading out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

comparing an advance of the readout locations designated on the basis of the control data with an advance of locations of the read addresses generated by said step of generating read addresses;

selecting, on the basis of a result of the step of comparing, addresses of a specific one of the waveform portions to be next read out, so as to generate the selected addresses of the specific waveform portion at a point where a phase of the waveform data read out on the basis of the read addresses coincides with a phase of the waveform data designated by the selected addresses; and

reproducing a waveform on the basis of the waveform data read out by said step of reading out the waveform data.

34. A method of reproducing a waveform using a waveform memory having stored therein waveform data of a plurality of waveform portions, said method comprising:

a tone-generation instructing step of instructing generation of a tone and designating a pitch of the tone;

a step of generating time-varying control data to control an advance of readout locations of the waveform portions;

an address generating step of generating read addresses advancing at a rate corresponding to the pitch designated by said tone-generation instructing step;

a readout step of reading out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

a control step of, for each predetermined reproduction period, making a comparison between an advance of virtual waveform portion locations designated on the basis of the control data and an advance of waveform portion locations designated by the read addresses generated by said address generating step and selects, on the basis of a result of the comparison, a specific one of the waveform portions to be next read out, so as to perform control such that said address generating step starts generating addresses of the specific waveform portion in a next reproduction period; and

a step of reproducing a waveform on the basis of the waveform data read out by said readout step.

35. A machine-readable storage medium containing a group of instructions for causing said machine to perform a method for reproducing a waveform using a waveform memory having stored therein waveform data of a plurality of waveform portions, said method comprising the steps of:

instructing generation of a tone;

designating a pitch of the tone;

generating time-varying control data to control an advance of readout locations of the waveform portions;

generating read addresses advancing at a rate corresponding to the pitch designated by said step of instructing generation of a tone;

reading out the waveform data of the waveform portions from said waveform memory on the basis of the read addresses;

comparing, for each of a predetermined reproduction period, an advance of virtual waveform portion locations designated on the basis of the time-varying control data and an advance of waveform portion locations designated by the read addresses generated by said step of generating read addresses;

selecting, on the basis of a result of the step of comparing, a specific one of the waveform portions to be next read out, so as to generate addresses of the specific waveform portion in a next reproduction period; and

reproducing a waveform on the basis of the waveform data read out by said step of reading out the waveform data.

36. A waveform generating device comprising:

a storage section that stores therein waveform data of a plurality of waveforms arranged in a time series;

a pitch designation section that presents tone pitch information designating a reproduced tone pitch;

a control information generation section that generates control information varying over time on the basis of a given variation rate that is unrelated to the reproduced tone pitch; and

a reproduction section including a readout section that reads out the waveform data from said storage section in response to the control information and the tone pitch information and at a given readout rate unrelated to said variation rate of the control information, said reproduction section reproducing the waveform data read out by said readout section at the reproduced tone pitch corresponding to said pitch information.

37. A waveform generating device as recited in claim 36 which further comprises a control data supply section, wherein said control data supply section supplies control data to said control information generating section to change the variation rate of the control information, and wherein said control information generation section changes the variation rate of the control information in accordance with the control data supplied via said control data supply section.

38. A waveform generating device as recited in claim 37 wherein said control information generation section includes an arithmetic operator and controls an inclination of the control information generated by said arithmetic operator in accordance with the control data supplied via said control data supply section.

39. A waveform generating device as recited in claim 36 wherein said readout section reads out a waveform segment including at least one wave cycle present at a time position indicated by the control information, in cycles corresponding to the tone pitch information and at a given readout rate unrelated to the variation rate of the control information.

40. A waveform reproduction device comprising:

a storage section that stores therein waveform data of a tone with vibrato imparted thereto;

a setting section that sets a vibrato-imparted segment of the waveform data as a loop segment; and

a reproduction section that repeatedly reproduces the loop segment set by said setting section, wherein said reproduction section stretches or compresses said waveform data in accordance with control information.

41. A waveform reproduction device as recited in claim 40 wherein said storage section prestores therein segment information indicative of the loop segment along with the waveform data, and said setting section sets the loop segment from among the waveform data in accordance with the segment information.

42. A waveform reproduction device as recited in claim 40 wherein said reproduction section includes:

a position information generation section that sequentially generates said control information in the form of position information, said position information sequentially varying at an optionally-set variation rate to designate a position in the waveform data according to an advance along a time axis;

a reproduction pitch designation section that designates a reproduction pitch; and

a waveform reproduction section that, in cycles corresponding to the reproduction pitch designated by said reproduction pitch designation section, reads out the waveform data at and around the position indicated by the position information to thereby reproduce a waveform.

43. A waveform reproduction device as recited in claim 42 wherein said position information generation section sequentially generates the position information in such a manner that once the position information reaches an end point of the loop segment by advancing in the loop segment in a forward direction along the time axis, the position information jumps back to a start point of the loop segment and again advances in the forward direction.

44. A waveform generating device comprising:

a control register storing pitch information and stretch/compression information;

a memory coupled to said control register, wherein said memory is adapted to store waveform data of a plurality of waveforms arranged in a time series, and wherein said memory is adapted to receive said pitch information from said control register;

a processor coupled to said control register, wherein said processor is adapted to receive pitch information and stretch/compression information from said control register, and wherein said processor generates control information designating a virtual readout address varying over time on the basis of a given variation rate that is unrelated to the reproduced tone pitch; and

a waveform data readout section coupled to said memory and said processor, wherein said waveform data readout section reads out the waveform data from said memory according to said control information received from said processor.

45. A method of generating a tone on the basis of a readout from a waveform memory having stored therein waveform data of a plural-cycle waveform, said method comprising the steps of:

storing waveform data of a plurality of waveforms arranged in a time series;

designating tone pitch information representative of a reproduced tone pitch;

generating control information varying over time on the basis of a given variation rate that is unrelated to the reproduced tone pitch; and

reading out the waveform data from said storage section in response to the control information and the tone pitch information, at a given readout rate unrelated to said variation rate of the control information, and at the reproduced tone pitch corresponding to said tone pitch information.

46. A waveform reproduction device comprising:

a memory adapted to store waveform data of a plurality of waveforms with vibrato characteristics imparted to at least one segment thereof;

a processor coupled to said memory, wherein said processor designates a vibrato-imparted segment of the waveform data as a loop segment; and

a waveform data readout section coupled to said memory and said processor, wherein said waveform data readout section repeatedly reads out said loop segment designated by said processor, and wherein said readout section stretches or compresses said waveform data in accordance with control information.

47. A method of reproducing a waveform using a waveform memory having stored therein waveform data of a plurality of waveform portions, said method comprising the steps of:

imparting vibrato characteristics to at least one segment of waveform data for a plurality of waveforms;

storing said waveform data;

designating a vibrato-imparted segment of said waveform data as a loop segment;

reading out said loop segment; and

stretching or compressing said waveform data in accordance with control information.