← Forrest Matter Piano Tuner

Your pianos

Each piano keeps its own stretch, temperament and session history.

Everything stays on this device and works offline.

New piano

Piano

Type

Keyboard

Pitch & temperament

Reference pitch (A4)
Cents from equal temperament, A = 0. Applied on top of the stretch.

Stretch

Stretch is how far the octaves are widened to match the piano’s own overtones. Measuring in the next step refines it for this piano.

Strings

How many keys have one, two or three strings. The typical layout for your piano type is filled in.

Triple (rest) 0

Guidance

Tolerance

Microphone

Close to the strings, away from fans.

Measure stretch

A2 Waiting for the note…
Stretch curve · ¢ vs equal this pianopreset

Inharmonicity B · log

The classic V: lowest around the middle, rising toward both ends.

A4
– –
PLAY THE NOTE
Strobe drifts left = flat
Spectrum
partial highlighted · dashed = target
Keyboard · tap a key to jump
  • Current
  • Done
  • Off target
  • To do

Session complete

Cents from target · every key Before After ±1 ¢

Free tune

–
Play any note The tuner finds the note and compares it with this piano’s stretched target.
PLAY ANY NOTE
Strobe drifts left = flat
Spectrum