A measurement of piano playing

Detachment rate

How often the melody is detached rather than joined.

What it sounds like

The same passage — Mozart K. 545, bars 1–4 — 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

Lina Yeh, 2023 — bars 1–4, detachment rate 34 %8 s
Mehmet Okonşar, 2014 — bars 1–4, detachment rate 36 %6 s

Most

Andreas Haefliger, 2003 — bars 1–4, detachment rate 79 %8 s
Alexei Lubimov, 2018 — bars 1–4, detachment rate 74 %7 s

How it is calculated

Share of melody steps with a gap of more than 10 per cent of the interval.

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
Bach Prelude in C270943
Gymnopédie 12311630
Träumerei31192437
Nocturne Op. 9/232253264
Brahms Op. 118/228283440
Fantaisie-Impromptu20263547
Pathétique II47354364
Chopin Étude 10/131304762
Clair de lune27415259
Chopin Ballade 412455460
Mozart K. 54537345479
Chopin Étude 10/1219455569
Ravel Pavane33566881
Schubert Op. 142/39496985
Nocturne Op. 48/127657179
Schubert Op. 90/343487299
Rachmaninoff Prelude29738289
Ravel Ondine61648391

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 1.96. noisy The transcription moves this dial about as far as pianists differ on it, so no claim should rest on where a single recording sits.