Subject: music pitch tracking From: "James W. Beauchamp" <jwbeauch@xxxxxxxx> Date: Sun, 29 Mar 2009 12:08:29 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Dear List, While we're on the subject of musical pitch tuning and tracking, since this is a subject I've been interested in for a long time, I would like to put in my 2 cents (maybe more). Musical pitch tracking is an old subject. Seashore published some in 1932 and Obata and Kobayashi in 1937 and 1938. Tove et al. described a system consisting of transistor electronics and a fast chart recorder in 1966. The idea is to plot melodies graphically to see what kinds of pitch and rhythmic changes occur over a substantial duration. As Tove et al. said, "The need for objective notation of time variations of frequency and amplitude in theoretical studies of musical phenomena is obvious and should have many applications in investigations of style, rythm (sic), and variations and deviations of key, in the study of conventional, modern, and folk music, as well as in basic studies of musical perception and creation." InterOcean Systems developed and marketed a real-time music analyzer called the Melograph in the 1970s, based on research by Charles Seeger at UCLA. It was contained in a compact rack-mounted package with an internal chart recorder and sold for about $8000. Unfortunately I couldn't afford to buy one. Since the advent of the computer, a plethora of pitch detectors/ trackers have been developed, and there's been too many to mention all of them. In 1989 at our lab at Univ. of Illinois at Urbana-Champaign, Rob Maher developed a nice one for music based on the short-time Fourier transform and a method called the "two-way mismatch (TWM) method", as part of his PhD thesis on musical sound source separation. This non-real-time program is contained in the SNDAN suite of programs that is available for free download and compilation on Unix systems (e.g., Linux or Mac OS X). A Windows/DOS version is also available. (See http://ems.music.uiuc.edu/beaucham/software/sndan/ ) This method also generates a chart-recorder-like image of musical pitch vs. time. Recently Ugar Guney developed a real-time version of the TWM method, which again is a free download and is platform independent if you have Java installed, called "freqazoid". This is definitely in beta form, but, again, it's free. I've also used the autocorrelation pitch detector in Praat and, after converting the frequency output to log form and graphing, have gotten similar results. This is also a free download. What is needed is a system that is accurate to a few cents but can also cover a wide range of pitch, at least 3 octaves, but 7 would be great. It should be able to handle a wide variety of waveforms, drop outs, a fair amount of noise and inharmonicity, and it should be able to handle very fast changes in pitch, i.e., it should be able to accurately transcribe virtuosic passages (64th notes, etc.), as well as glides, vibrato, and portamento. Besides displaying the data on a log(f0) vs. time chart, the system should also be able to generate the data to a file for subsequent post-processing research. Conversion to MIDI and musical notation are nice features, but these are already available in programs once the log(f) data is provided. I see that G-tune, which has now merged with Peterson Electro-Musical Products, has morphed into StroboSoft 2.0. This contains a vast number of tuning features, but the feature that I'm most interested in is its "pitch graph", which is only provided in the deluxe version ($100). Unfortunately, they don't spec the accuracy, range, and speed of this graphing tool. I would also like to mention that our group is also interested in polyphonic pitch detection, i.e., simultaneous pitch transcription of more than one voice at a time. Some progress in this field has been made during the last few years. Recently Anssi Klapuri and Tuomas Virtanen have made a good summary of these efforts (see below). Jim Beauchamp Univ. of Illinois at Urbana-Champaign References Seashore, C. E., "The Vibrato", in Studies in the Pschology of Music, Vol. 1, U. of Iowa (1932). Obata, J. and R. Kobayashi, "A Direct Reading Pitch Recorder and its Applications to Music and Speech", J.A.S.A. Vol 9 (1937). Obata, J. and R. Kobayahsi, "An Apparatus for Direct Recording the Pitch and Intensity of Sound", J.A.S.A. Vol 10 (1938). Seeger, J., "Toward a universal music sound-writing for musicology", Int. Folk Music Council, Vol. 9 (1957). Tove., P. A., B. Norman, L. Isaksson, and J. Czekajewski, "Direct- Recording Frequency and Amplitude Meter for Analyzing of Musical and Other Sonic Waveforms", J. A. S. A. Vol. 39 (1966). Boersma, P., "Accurate short-term analysis of the fundamental frequency and the harmonics-to-noise ratio of a sampled sounds", Proc. Inst. Phonetic Sciences, Vol 17, Amsterdam (1993). Maher, R. C. and J. W. Beauchamp, "Fundamental frequency estimation of musical signals using a Two-Way Mismatch procedures", J. A. S. A., Vol. 95 (1994). Klapuri, A. and T. Virtanen, "Automatic Music Transcription", Handbook of Signal Processing in Acoustics, Vol. 1, Springer (2008).