A measurement of piano playing

Rolled fraction

How often block chords are rolled at all.

What it sounds like

The same passage — Träumerei, bars 2–3 — 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.

Least

Walter Gieseking, 1955 — bars 2–3, rolled fraction 13 %10 s
Lise de la Salle, 2014 — bars 2–3, rolled fraction 16 %10 s

Most

Jean-Marc Luisada, 2018 — bars 2–3, rolled fraction 93 %9 s
Valentina Lisitsa, 2008 — bars 2–3, rolled fraction 87 %10 s

How it is calculated

Share of block chords spread by more than 30 ms.

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
Chopin Étude 10/1312841
Mozart K. 5453711838
Chopin Étude 10/121972540
Rachmaninoff Prelude29133051
Pathétique II47133456
Chopin Ballade 412283454
Nocturne Op. 48/127243652
Gymnopédie 123103981
Schubert Op. 142/39334051
Fantaisie-Impromptu20314359
Nocturne Op. 9/232164472
Ravel Pavane33134572
Träumerei31134793
Clair de lune27234878
Schubert Op. 90/343214982
Ravel Ondine61354962
Brahms Op. 118/228246285

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