Apparatus and method for searching a melody

• US 5,874,686 A
• Filed: 10/31/1996
• Issued: 02/23/1999
• Est. Priority Date: 10/31/1995
• Status: Expired due to Fees

• Current Assignee: Asif Ghias
• Original Assignee: Asif U. Ghias, David W. Chamberlin, Jonathan A. Logan
• Inventors: Ghias, Asif U., Logan, Jonathan A., Chamberlin, David W.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): DONELS, JEFFREY
• Application Number:
  US08/742,260
• Time in Patent Office: 845 Days
• Field of Search: 84/600, 84/609, 84/634, 84/616, 84/654
• US Class Current: 84/609
• CPC Class Codes: G06F 16/634 Query by example, e.g. query by humming
• CPC Class Codes: G06F 16/683 using metadata automatically derived from the content
• CPC Class Codes: G10H 1/0041 in coded form
• CPC Class Codes: G10H 2210/066 for pitch analysis as part of wider processing for musical purposes, e.g. transcription, musical performance evaluation; Pitch recognition, e.g. in polyphonic sounds; Estimation or use of missing fundamental
• CPC Class Codes: G10H 2240/071 Wave, i.e. Waveform Audio File Format, coding, e.g. uncompressed PCM audio according to the RIFF bitstream format method
• CPC Class Codes: G10H 2240/141 Library retrieval matching, i.e. any of the steps of matching an inputted segment or phrase with musical database contents, e.g. query by humming, singing or playing; the steps may include, e.g. musical analysis of the input, musical feature extraction, query formulation, or details of the retrieval process
• CPC Class Codes: G10H 2250/135 Autocorrelation
• CPC Class Codes: G10H 2250/251 Wavelet transform, i.e. transform with both frequency and temporal resolution, e.g. for compression of percussion sounds; Discrete Wavelet Transform [DWT]

Abstract

Apparatus and method for easily, efficiently, and accurately searching melodies. A melody is inputted to a computer and converted into a form of a sequence of digitized representations of relative pitch differences between successive notes thereof. A melody database is searched for at least one sequence of digitized representations of relative pitch differences between successive notes which at least approximately matches the sequence of digitized representations of relative pitch differences between successive notes of the melody.

Claims

1. Apparatus for searching a melody comprising a computer means having a database of melodies each including a plurality of notes in a form of a sequence of digitized representations of relative pitch differences between successive notes, means for inputting a melody to said computer means, means for converting the melody into a form of a sequence of digitized representations of relative pitch differences between successive notes thereof, and means for searching said melody database for at least one sequence of digitized representations of relative pitch differences between successive notes which at least approximately matches said sequence of digitized representations of relative pitch differences between successive notes of the melody.

2. Apparatus according to claim 1 wherein said input means comprises a microphone.

3. Apparatus according to claim 1 further comprising means for outputting from said computer a ranked list of approximately matching melodies.

4. Apparatus according to claim 1 wherein said converting means comprises an autocorrelation based pitch detector means.

5. Apparatus according to claim 1 wherein said converting means comprises an autocorrelation based pitch detector means having low-pass filter means for removing non-vocal frequencies and center-clipping means for eliminating unwanted formant structure.

6. Apparatus according to claim 1 wherein said converting means comprises a wavelet pitch tracker.

7. Apparatus according to claim 1 wherein said converting means comprises a cubic spline wavelet pitch tracker.

8. Apparatus according to claim 1 further comprising means for approximately matching sequences of digitized representations of relative pitch differences between successive notes.

9. A method for searching a melody comprising the steps of:

(a) selecting a computer means having a database of melodies each including a plurality of notes in a form of a sequence of digitized representations of relative pitch differences between successive notes, (b) inputting a melody to the computer means, (c) converting the melody into a form of a sequence of digitized representations of relative pitch differences between successive notes thereof, and (d) searching the melody database for at least one sequence of digitized representations of relative pitch differences between successive notes which at least approximately matches the sequence of digitized representations of relative pitch differences between successive notes of the melody.

10. A method according to claim 9 wherein the step of inputting the melody comprises humming into a microphone.

11. A method according to claim 9 further comprising operating the computer to output a ranked list of approximately matching melodies.

12. A method according to claim 9 wherein the step of converting comprises applying to the sequence of representations of relative pitch changes between successive notes of the hummed melody an autocorrelation based pitch detector.

13. A method according to claim 9 wherein the step of converting comprises applying to the sequence of representations of relative pitch changes between successive notes of the hummed melody an autocorrelation based pitch detector having low pass filtering for removing non-vocal frequencies and center-clipping for eliminating unwanted formant structure.

14. A method according to claim 9 wherein the step of converting comprises applying to the sequence of representations of relative pitch changes between successive notes of the hummed melody a wavelet pitch tracker.

15. A method according to claim 9 wherein the step of converting comprises applying to the sequence of representations of relative pitch changes between successive notes of the hummed melody a cubic spline wavelet pitch tracker.

16. A method according to claim 9 further comprising operating the computer means to obtain approximate matches of sequences of digitized representations of relative pitch differences between successive notes.