Violin pitch detection
J. Kohut, M. V. Mathews, Joan E. Miller, Paul Zukofsky · The Journal of the Acoustical Society of America · 1981
An instrumentation for measuring and recording the pitches produced by a violinist is described. The four strings are measured simultaneously and independently so chords, as well as single pitches, can be studied. Measurements are made with an accuracy of one part in 4096. A special bridge, which has a ceramic microphone under each string, is attached to the violin. Signals from the microphones go into four pitch period detectors, the design of which is facilitated by the sawtooth shape of string oscillations. The duration of each period is measured by counting the number of cycles of an 800-kHz clock in the period. These counts are then read into a computer at rates determined by a user-specified setting of an external oscillator. The pitches are thus available for real-time displays which are presented to the performer on a CRT and/or are stored for post-processing and analysis. This facility provides an effective means for detailed studies of performance practices such as vibrate, shifting, and matters of intonation.