A measurement of piano playing

Emergent voice

How often a player brings out a line that the other players of the same piece leave inside the texture.

What it sounds like

The same passage — Nocturne Op. 9/2, bars 10–11 — 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

Alice Sara Ott, 2021 — bars 10–11, emergent voice 1.32 /10 bars15 s
Maurizio Pollini, 2005 — bars 10–11, emergent voice 1.32 /10 bars13 s

Most

Yundi Li, 2010 — bars 10–11, emergent voice 3.42 /10 bars15 s
Lang Lang, 2025 — bars 10–11, emergent voice 3.16 /10 bars16 s

How it is calculated

Every note is expressed relative to that player's own melody level nearby; the median across all players is the consensus for that note; a run of notes played well above consensus — after removing the player's own overall offset — is one event. Counted per ten bars. This is the only measure here that is defined against what other pianists did.

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 C270.000.000.00
Chopin Étude 10/1310.000.250.63
Gymnopédie 1230.000.510.90
Mozart K. 545370.481.112.26
Fantaisie-Impromptu200.801.181.81
Brahms Op. 118/2280.321.292.02
Ravel Ondine610.951.472.11
Rachmaninoff Prelude290.821.482.46
Träumerei310.611.522.73
Clair de lune270.831.552.39
Nocturne Op. 48/1270.911.562.21
Pathétique II470.961.642.60
Chopin Ballade 4121.341.672.01
Schubert Op. 142/391.251.942.55
Ravel Pavane331.532.082.64
Schubert Op. 90/3431.402.093.14
Nocturne Op. 9/2321.322.113.42
Chopin Étude 10/12190.952.142.86

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 0.51. fair Usable, but the error is worth stating alongside any single value.