Tuner is a software chromatic tuner for determining the musical pitch of a sound as well as how close that pitch is to the established value for the note. Tuner listens on the NeXT's CODEC microphone input and computes a frequency for the sound it samples. It maps this frequency onto a musical note and displays the value. Then it looks up the standard value for the note to display the difference between the standard value and the computed frequency.
The tuner can compute pitch using two different algorithms, by counting zero transitions and by doing a fast Fourier transformation (FFT) using the DSP array routines. You need a relatively simple waveform for the zero transitions algorithm to work -- some instruments and voices work better than others. When it works, it has a potential accuracy of about +/- 1/4 Hz. The FFT algorithm is able to handle more complex waveforms but currently only has a potential accuracy of about +/- 2 Hz. (The zero transitions algorithm works well with recorders and the FFT algorithm works better with bassoons.) The potential range of both algorithms is C00 to B7 and both are further constrained by the limits of the microphone.
Read the help panel or Tuner.rtf for details about how to use this utility.
Tuner is ShareWare, if you use it please chip in $7.50 (1/10 the cost of a real chromatic tuner :-). Please include an EMail address with your payment if you're interested in update notices. There is no warranty provided with this software -- full sources are provided and bug reports are welcome.
This software copyright 1992 -- all rights reserved.
Christopher Lane
1843 Lenolt Street
Redwood City, CA 94063-1068
lane@sumex-aim.stanford.edu
The nature of ShareWare is that you're able to purchase a less than polished program at a fraction of the price of commercial software. By purchasing a ShareWare program in the early stage of it's development, you are helping to foster it along and provide the positive feedback that will allow it grow into a polished application. By using ShareWare, but not contributing, due to bugs or other reasons, you're working against the chances of the program improving, and if/when an improved version does appear, the ShareWare price will typically be higher, reflecting the program's steady progress towards commercial quality. For the best payoff on your investment, contribute early in the cycle.
