The Pitch Room
Ref. 03
Every key has a number.
Play any key below. You’ll hear it, see its exact frequency, and find out how many strings it has inside the piano. Switch the reference pitch to hear how a whole orchestra’s tuning shifts.
Tip · sound needs a tap or click first; some phones mute web audio in silent mode.
Behind the numbers
Three ideas every tuner works with.
01
× 1.0595
Equal temperament
Each semitone is the twelfth root of two above the last. Every key sounds equally in tune, and none is perfectly pure.
02
+ 30 cents
Stretch tuning
Piano strings are stiff, so their overtones run sharp. We stretch octaves slightly so the top and bottom agree with the middle.
03
0 beats
Clean unisons
Most notes have two or three strings. When they agree exactly, the beating disappears and the note blooms.
Reference pitch
Where should A sit?
432 Hz
Alternative tuning
Popular in some recording circles. We’ll tune to it on request, though it lowers tension on older strings.
435 Hz
French diapason, 1859
The first official standard. Some historic pianos are still happiest here.
440 Hz
International standard
Adopted as ISO 16. Our default for homes, schools and most ensembles.
443 Hz
Vienna concert pitch
Common with orchestras and halls in Central Europe. Brighter and a touch more brilliant.
Hear the difference on your own piano.
Book a tuning