Tuner & Pitch Pipe

Two tools choir leaders and singers reach for constantly, in one uncluttered app.

The tuner listens through the microphone, detects pitch with the YIN algorithm implemented from the paper, and shows a large note name with a cents offset from −50 to +50. Colour tells you at a glance whether you are in tune, close, or off.

The pitch pipe gives a twelve-note circular selector across three octaves, with a choice between a pure sine tone and a richer harmonic “pipe” voice. Volume and last-used settings are remembered between sessions.

The interesting engineering was in the detector: getting stable, low-latency pitch readings from a phone microphone without the needle jittering meant careful windowing and thresholding on top of YIN’s difference function.