A measurement of piano playing

Accompaniment legato

The same overlap measure, applied to the accompaniment.

What it sounds like

The same passage — Pathétique II, 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

Arthur Rubinstein, 1995 — bars 1–4, accompaniment legato -0.74 ratio16 s
Wilhelm Kempff, 1956 — bars 1–4, accompaniment legato -0.73 ratio14 s

Most

Stephen Kovacevich, 1972 — bars 1–4, accompaniment legato 0.05 ratio22 s
Paul Lewis, 2007 — bars 1–4, accompaniment legato 0.02 ratio19 s

How it is calculated

Key-overlap ratio over the accompanying figuration.

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
Nocturne Op. 48/127-0.73-0.69-0.51
Ravel Ondine61-0.60-0.51-0.28
Nocturne Op. 9/232-0.66-0.430.10
Clair de lune27-0.50-0.35-0.09
Pathétique II47-0.74-0.330.05
Schubert Op. 90/343-0.43-0.32-0.12
Rachmaninoff Prelude29-0.38-0.29-0.19
Schubert Op. 142/39-0.36-0.240.05
Mozart K. 54537-0.42-0.23-0.06
Chopin Étude 10/1219-0.30-0.15-0.06
Fantaisie-Impromptu20-0.23-0.11-0.01
Chopin Ballade 412-0.26-0.100.01
Chopin Étude 10/131-0.26-0.080.19
Brahms Op. 118/228-0.110.040.59
Träumerei31-0.010.110.25
Gymnopédie 1230.070.120.18
Bach Prelude in C27-0.200.141.07

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 1.60. 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.