PianoTuner

Based on Ryan Kinnett's GuitarTuner, this program automatically detects which note is being played into the computer microphone. When the sound is tuned to within 0.05 tones of the nearest note, the display indicates a match. The keyboard display provides a graphical indicator of which note was being matched. The program purposefully shows the middle octave only, since it's better to tune the other octaves by ear anyway.

The display refresh rate can be set using a slider bar. Faster refresh rates require a faster CPU, but provide quicker feedback while tuning. Slower refresh rates provide more spectral detail, and can help indicate when unison strings are mistuned (e.g., multiple peaks in the sound spectrum).