432 Hz converter

Concert pitch puts the A above middle C at 440 Hz, and nearly all recorded music is tuned to it. Tuned to A = 432 Hz instead, every note is 1.8% lower: 31.8 cents, about a third of a semitone. The song keeps its speed, its key name and its length; only the tuning changes.

Some listeners find 432 Hz warmer or calmer. Claims of health effects rest on a few small studies rather than large controlled trials, so take it as a matter of taste.

Not every recording sits exactly on 440. Older records, tape transfers and some bands drift a few cents sharp or flat. AudioRinse measures the tuning from the song itself and moves it by exactly what's needed to land on 432, so a song at 438 Hz isn't lowered too far. A song that's already at 432 is left as it is, and the page says so.

Other targets are one click away: back to A = 440 Hz for a song that was tuned to 432, or A = 444 Hz.

Played faster, a record also plays higher; slowed down, it plays lower. AudioRinse keeps the two apart with Signalsmith Stretch, an open-source pitch and time-stretching library made for music with many instruments at once. It cuts the sound into short overlapping slices, moves each slice's frequencies or its timing, and joins them back up, here in your browser.

You hear every change as the song plays, and the download is made the same way, faster than real time. On test tones every pitch we checked, from an octave down to an octave up, landed within 2 cents of the target, and every speed gave exactly the expected length.