A measurement of piano playing

Melody float

Whether the tune lands with the accompaniment underneath it, or leans behind it.

What it sounds like

The same passage — Schubert Op. 90/3, bars 1–2 — from the recordings that sit lowest and highest on this measurement. Every clip is a note list replayed on one sampled grand at one gain, so the only difference you are hearing is the playing.

Least

Vladimir Horowitz, 1973 — bars 1–2, melody float 88 ms8 s
Alfred Brendel, 1962 — bars 1–2, melody float 97 ms9 s

Most

Mikhail Pletnev, 2013 — bars 1–2, melody float 416 ms9 s
Simone Dinnerstein, 2012 — bars 1–2, melody float 345 ms10 s

How it is calculated

Melody onset minus the time predicted by interpolating the running accompaniment figure in the other hand. Positive means the melody is behind. Only meaningful where the figuration is actually running: in some engravings the accompaniment is written in the upper staff and the measure is not reported.

How much pianists differ on it

Every piece in the library, with the range across its recordings. The units mean the same thing in every row, except for basic tempo, which is in each piece’s own beat.

PieceRecordingsLowestMedianHighest
Pathétique II47-65-2139
Schubert Op. 142/39-23-84
Clair de lune27-52155
Chopin Étude 10/1219-30220
Chopin Ballade 412-28244
Nocturne Op. 9/232-53236
Mozart K. 54537-10449
Nocturne Op. 48/127-40489
Fantaisie-Impromptu20-441690
Ravel Ondine61-213595

How reliably it can be measured

A Disklavier capture — the pianist’s own key sensors, no microphone — was rendered to audio, transcribed as if it were a recording, and re-measured. The error the transcription step introduces, as a multiple of how far pianists actually differ on this dial, is 0.09. solid This dial survives transcription intact: where one recording sits on it can be argued from.