A measurement of piano playing

Basic tempo

How fast the piece goes overall.

What it sounds like

The same passage — Gymnopédie 1, bars 5–7 — 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

Reinbert de Leeuw, 1980 — bars 5–7, basic tempo 41 bpm13 s

Jeroen van Veen, 2014 — bars 5–7, basic tempo 43 bpm18 s

Most

Klára Körmendi, 1992 — bars 5–7, basic tempo 96 bpm6 s

Alessandra Celletti, 2022 — bars 5–7, basic tempo 86 bpm6 s

How it is calculated

60 divided by the median time between beats. The beat is the piece's own notated beat, so the number is only comparable between recordings of the same work.

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.

Piece	Recordings	Lowest	Median	Highest
Pathétique II	47	23	29	37
Nocturne Op. 9/2	32	30	36	45
Schubert Op. 142/3	9	40	44	54
Clair de lune	27	35	46	58
Chopin Ballade 4	12	45	48	52
Ravel Pavane	33	39	50	68
Nocturne Op. 48/1	27	45	54	66
Träumerei	31	42	54	71
Ravel Ondine	61	47	55	63
Schubert Op. 90/3	43	54	63	86
Bach Prelude in C	27	50	70	107
Gymnopédie 1	23	41	72	96
Brahms Op. 118/2	28	58	74	92
Rachmaninoff Prelude	29	63	82	120
Mozart K. 545	37	120	133	152
Chopin Étude 10/12	19	127	147	161
Fantaisie-Impromptu	20	130	148	166
Chopin Étude 10/1	31	151	174	193

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 0.06. solid This dial survives transcription intact: where one recording sits on it can be argued from.

All measurements