Temperament Laboratory

The Well-Tempered Clavier, retuned

Pick a prelude and fugue from the Well-Tempered Clavier, Book I — or add your own MIDI — then listen through a chosen historical or corpus-derived temperament. Each key below shows how far it sits from equal temperament, and lights as it sounds — switch temperaments while playing to hear the same prelude change character.

Choose a piece Pick from the Well-Tempered Clavier below, or add your own .mid files. Nothing leaves your machine.
No piece loaded cents vs. equal temperament
0:00 / 0:00
Custom temperament

Paste 13 ratios (C=1 … G=1.5 … octave=2) or 12 cent values from C. The Bach-chorale set is prefilled.