One octave of strings, each a little flat. A tuner sets them in a fixed order, every string against one already set, by listening to the beat between the two notes.
Turn the lever to tighten a string. The beat slows as the string comes up. Stop when it keeps the pendulum’s pace.
Sound on. Drag anywhere to turn the lever, or use the arrow keys.
Cents from equal temperament. A cent is a hundredth of a semitone. Tap a string to play it.
No. 011 by Mahir Yavuz. The inside of a grand piano, seen from the keyboard: tuning pins in the plate, steel strings running away over the hammers and dampers, a felt strip muting all but one string of each note, a tuning fork and a tuning lever. Thirteen strings, from A3 to A4, start a little flat, differently on every visit.
The visitor tunes them in the order an aural tuner uses. A4 is set to the fork. A3 is set an octave below it. Then every other note is set against one already tuned, going round by fifths and fourths: E4, B3, F♯4, C♯4, G♯4, D♯4, A♯3, F4, C4, G4 and D4. Two notes sound together, and the coinciding overtones beat. Turning the lever tightens the string and the beat slows. Octaves are tuned until the beat stops. Fifths are left a little narrow and fourths a little wide, so they beat slowly, about three to six times in four seconds; a pendulum swings at the pace to match. At the end the page plays chords on the tuning and shows how many cents each note is from equal temperament.
The sound is made in the browser with Web Audio. Nothing is recorded.