Detection of musical gestures

• US 4,829,872 A
• Filed: 05/10/1988
• Issued: 05/16/1989
• Est. Priority Date: 05/11/1987
• Status: Expired due to Fees

• Current Assignee: Fairlight Instruments Pty Limited
• Original Assignee: Fairlight Instruments Pty Limited
• Inventors: Connolly, Wayne P., Topic, Michael W.
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US07/192,322
• Time in Patent Office: 371 Days
• Field of Search: 84/1.01, 84/1.03, 84/105, 84/453, 84/454, 84/DIG. 18
• US Class Current: 84/453
• CPC Class Codes: G10G 3/04 using electrical means
• CPC Class Codes: G10H 3/00 Instruments in which the tones are generated by electromechanical means

Abstract

Musical information is analyzed in terms of pitch and/or amplitude to provide an output which is useful in controlling musical synthesizers but may have other applications also. By controlling music synthesizers, synthesized sounds may be played in synchronism with source music. Detection of musical gestures occurs in the present improved method, a musical gesture being the onset or cessation of individual notes comprising a musical performance or the like. The method comprises measuring at selected points in time the pitch and/or amplitude of the musical signal, calculating the change in pitch and amplitude at intervals, calculating the change of said changes in pitch and/or amplitude at intervals, comparing these change of changes to threshold values, and providing the change of changes in pitch and/or amplitude exceeds the threshold, generating a signal signifying the onset of the musical gesture.

Claims

1. A method of determining the onset of a musical gesture comprising the steps of measuring at selected points in time the pitch of a musical signal, calculating the change in pitch between the measurements, calculating the change between successive ones of said changes in pitch, comparing said change of changes to threshold values and in the case that the change of changes in pitch exceeds said threshold generating a signal signifying the onset of the musical gesture.

2. A method as claimed in claim 1 including the step of disabling the gesture detection process for a specified period equal to the smallest interval between gestures which can be realistically generated by a human performer.

3. A method as claimed in claim 1 including the step of filtering the musical signal so as to remove frequencies outside a selected frequency range.

4. A method as claimed in claim 3 including the steps of measuring at selected points in time the amplitude of a musical signal calculating the change in amplitude between the measurements calculating the change between successive ones of said changes in amplitude, comparing said change of changes to threshold values and in the case that the change of changes in amplitude exceeds said threshold generating a signal signifying the onset of the musical gesture.

5. A method of determining the onset of a musical gesture comprising the steps of measuring at selected points in time the pitch of a musical signal, calculating the change in pitch between the measurements, calculating the change between successive ones of said changes in pitch, comparing said change of changes to threshold values and in the case that the change of changes in pitch exceeds said threshold generating a signal signifying the onset of the musical gesture, the method including the steps of measuring at selected points in time the amplitude of a musical signal calculating the change in amplitude between the measurements calculating the change between successive ones of said changes in amplitude, comparing said change of changes to threshold values and in the case that the change of changes in amplitude exceeds said threshold generating a signal signifying the onset of the musical gesture.

6. A method of determining the onset of a musical gesture comprising the steps of measuring at selected points in time the amplitude of a musical signal, calculating the change in amplitude between the measurements, calculating the change between successive ones of said changes in amplitude comparing said change of changes to threshold values and in the case that the change of changes in amplitude exceeds said threshold generating a signal signifying the onset of the musical gesture.

7. A method as claimed in claim 6 including the step of disabling the gesture detection process for a specified period equal to the smallest interval between gestures which can be realistically generated by a human performer.

8. A method as claimed in claim 6 including the step of providing an output signal indicative of the rate of amplitude change at the time of detection of a gesture.

9. A method as claimed in claim 8 including the step of filtering the musical signal to remove frequencies outside a selected frequency range.

10. A method of determining the onset of a musical gesture comprising the steps of measuring at selected points in time the amplitude of a musical signal, calculating the change in amplitude between the measurements, calculating the change between successive ones of said changes in amplitude comparing said change of changes to threshold values and in the case that the change of changes in amplitude exceeds said threshold generating a signal signifying the onset of the musical gesture, including the step of filtering the musical signal to remove frequencies outside a selected frequency range.

11. A detector for detecting the onset of a musical gesture comprising a pitch detector for measuring at selected points in time the pitch of a musical signal, the pitch detector being arranged to be connected to a means for calculating the change in pitch between the measurements and calculating the change between successive ones of said changes in the pitch and comprising a comparator arranged to compare said change of changes to threshold values and to generate a signal signifying the onset of the musical gesture when the change of changes in the pitch exceeds the threshold values.

12. A detector as claimed in claim 11 comprising a disabling means for disabling the gesture detection process for a specified period equal to the smallest interval between gestures which can be realistically generated by a human performer.

13. A detector as claimed in claim 11 comprising a filter which is arranged to filter the musical signal and remove frequencies outside a selected frequency range.

14. A detector as claimed in claim 13 comprising an amplitude detector for measuring at selected points in time the amplitude of a musical signal and the amplitude detector having an output connected to a means for calculating the change in amplitude between the measurements and calculating the change between successive ones of said changes in the amplitude and comprising a comparator arranged to compare said change of changes in amplitude and to generate a signal signifying the onset of the musical gesture when the change of changes in amplitude exceeds the threshold values.

15. A detector comprising an amplitude detector for measuring at selected points in time the amplitude of a musical signal, the amplitude detector being arranged to be connected to the rate of change means and the rate of change means being arranged to calculate the change in amplitude between the measurements and calculate the change between successive ones of said changes in amplitude, the rate of change means being arranged to compare the change of changes to threshold values and generate a signal signifying the onset of the musical gesture when the change of changes in amplitude exceeds said threshold values.

16. A detector as claimed in claim 15 comprising a disabling means for disabling the gesture detection process for a specified period equal to the smallest interval between gestures which can be realistically generated by a human performer.

17. A detector as claimed in claim 16 or 17 comprising a filter which is arranged to filter the musical signal and remove frequencies outside a selected frequency range.

18. A detector for determining the onset of a musical gesture comprising a pitch and amplitude detector for measuring at selected points in time the amplitude and pitch of a musical signal and having an output connected to a means for calculating the change in pitch and amplitude between the measurements and calculating the change between successive ones of said changes in the pitch and amplitude and comprising a comparator arranged to compare said change of changes to threshold values and to generate a signal signifying the onset of a musical gesture when the change of changes in pitch or amplitude exceeds the threshold values.