A measurement of piano playing
How much one melody note is held into the next — finger legato.
The same passage — Bach Prelude in C, bars 1–3 — 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.
Key-overlap ratio: (offset of a note minus onset of the next) divided by the interval between them. Positive means the notes overlap; negative means there is a gap.
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.
| Piece | Recordings | Lowest | Median | Highest |
|---|---|---|---|---|
| Rachmaninoff Prelude | 29 | -0.59 | -0.52 | -0.46 |
| Nocturne Op. 48/1 | 27 | -0.62 | -0.51 | -0.41 |
| Ravel Ondine | 61 | -0.60 | -0.46 | -0.29 |
| Ravel Pavane | 33 | -0.57 | -0.43 | -0.33 |
| Schubert Op. 90/3 | 43 | -0.54 | -0.39 | -0.06 |
| Schubert Op. 142/3 | 9 | -0.51 | -0.30 | -0.07 |
| Chopin Étude 10/12 | 19 | -0.35 | -0.17 | -0.03 |
| Chopin Ballade 4 | 12 | -0.23 | -0.14 | -0.03 |
| Mozart K. 545 | 37 | -0.36 | -0.13 | -0.02 |
| Clair de lune | 27 | -0.28 | -0.13 | 0.07 |
| Chopin Étude 10/1 | 31 | -0.23 | -0.08 | 0.19 |
| Fantaisie-Impromptu | 20 | -0.08 | 0.01 | 0.08 |
| Pathétique II | 47 | -0.47 | 0.01 | 0.07 |
| Nocturne Op. 9/2 | 32 | -0.25 | 0.04 | 0.08 |
| Brahms Op. 118/2 | 28 | 0.02 | 0.08 | 0.18 |
| Träumerei | 31 | 0.01 | 0.09 | 0.18 |
| Gymnopédie 1 | 23 | 0.06 | 0.12 | 0.18 |
| Bach Prelude in C | 27 | -0.02 | 0.28 | 1.30 |
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.