# Show HN: Claude Plays the Piano from Braille > Source: > Published: 2026-10-26 20:00:14+00:00 ## gottschalk-tarantelle-espadero.mp4 An expressive MIDI performance, decoded from the braille transcription of the score. The piece is Nicolás Ruiz Espadero's transcription for piano alone, Boston: Oliver Ditson, 1874. | File | What it is | |---|---| | `espadero.brf` | The score in North American ASCII music braille, bar-over-bar: Hu Haipeng's transcription for the Braille Orchestra and Open Braille Music projects ( [IMSLP #933069](https://imslp.org/wiki/Grande_Tarantelle%2C_Op.67_%28Gottschalk%2C_Louis_Moreau%29) , CC BY-SA 4.0) | | `brf.py` | Reads the braille into timed notes (the subset of the BANA Music Braille Code the file uses); prints the decoded notes bar by bar | | `perform.py` | Turns the notes into the performance: tempo, rubato, dynamics, voicing, articulation, pedal | | `render.swift` | Plays a MIDI file through the macOS sampler, offline, into an `.m4a` | | `gottschalk-tarantelle-espadero.mid` | The performance | | `gottschalk-tarantelle-espadero.m4a` | The performance as audio | | `LICENSE-MIT` | The MIT license, for the code | | `LICENSE-CC-BY-SA-4.0` | Creative Commons Attribution-ShareAlike 4.0 International, for the braille, the performances and the rest | The Python needs only the standard library (3.11 or later); `render.swift` needs macOS and Swift (the Xcode command-line tools). ``` python3 perform.py espadero.brf -o gottschalk-tarantelle-espadero.mid swift render.swift gottschalk-tarantelle-espadero.mid gottschalk-tarantelle-espadero.m4a python3 brf.py espadero.brf 1 12 # the decoded notes of bars 1-12 ``` `perform.py --report` prints the tempo, loudness and markings of every bar; `--tempo` sets the dotted-quarter tempo (158), `--no-repeats` skips the two repeats. For a better piano, open the `.mid` in GarageBand: **File › Open**, or drag it into an empty project. When GarageBand asks *Also import tempo information?*, click **Import Tempo**: the rubato lives in the tempo map, and without it the piece plays metronomically. If the track does not come up as a piano, pick **Piano › Steinway Grand Piano** in the Library. Bars and key changes line up with the score, so it reads correctly in a DAW or notation program too. `render.swift` cannot use GarageBand's Steinway itself: it is an EXS24 instrument over one consolidated `.caf`, which `AVAudioUnitSampler` will not load (error -10868). The braille gives every pitch and duration exactly, so no optical reading of the 1874 scan was needed. The decoder handles the code as this file uses it: octave marks and BANA's rules for unmarked octaves, intervals read down in the right hand and up in the left, interval doubling (`--`), full- and part-measure in-accord, measure and part-measure repeats (whose extent comes from the bar's length), 16th-note grouping, triplets and quintuplets, stem signs, grace and cue-size notes, cautionary accidentals (in parentheses in print, `,'` … `,'` in the braille), ties, slurs, fingered tremolos, hand changes within a line, first and second endings, and key changes. Every voice of all 539 bars (and the two second endings) adds up to exactly 6/8. Bars were compared with the Ditson print (IMSLP #07731) in every section. Six places in the braille differ from the print and are corrected in `brf.py` (`CORRECTIONS`): | Bars | Braille | | |---|---|---| | 2, 3, 5, 440, 444, 446 | Left-hand A major chord as A2 C♯3 E3 | A2 E3 C♯4 (the tenth needs an octave mark the braille lacks) | | 489 | A stray `5k` after the third note | Nothing; without it the bar is exactly 6/8 | The braille leaves out the print's *ossia* and *Facilité* staves, so they are not played. The cue-size notes the score marks *avec les petites notes ad lib.* (bars 309–322) are played, softly. Everything beyond the notes is an interpretation layered over the score's own markings: - **Tempo** :*Tempo di Tarantella* at ♩. = 158, with a light lilt on each beat. Each four-bar phrase presses forward a little and eases at its cadence. The music broadens into double bars and key changes and takes a breath after them.*animando* presses about 7% into its climax, rides it, then settles.*dolce* and*pesante* are a shade slower.*Più mosso* (bar 498) is about 11% faster to the end. Fermatas are held about twice their length, and the last line is broad. - **Dynamics** : the printed levels,*fp* ,*sf* /*rfz* ,*cresc.* /*dim.* (ramping to the next printed level) and hairpins (as swells). Where the print gives none, the orchestral*Tutti* enters at least*f* , and an unmarked*Solo* after it steps down to*f* . On top of that, the melody grows as it rises above its surroundings, beat 1 of each bar (and beat 2, less) is stressed, and eight-bar arcs give it shape.*legg.* ,*scherz.* and*scintillante* are lighter;*martellato* ,*pesante* and*con impeto* heavier. - **Voicing** : the top of each right-hand chord is louder, inner notes recede, and the bass is firm. - **Chords** : no chord lands all at once. Each hand places its chord separately, the left hand usually a few milliseconds ahead. Within a hand the notes fan out, mostly from the bottom up, over about 10 ms for an octave to 20–40 ms for a big chord, wider the more notes and the wider the stretch. The melody note leads in the right hand and the bass in the left. A chord never fans out over more than a third of the time to that hand's next one, so fast repeated chords stay crisp. Printed arpeggios roll from the bottom at about 30 ms a note. - **Touch** : staccato and staccatissimo are short, slurs and held stems legato, accents, marcato and tenuto as printed, and unmarked notes slightly detached. - **Pedal** : as the braille marks it, each*Ped.* lifting and catching again just after the beat. - **Ornaments** : grace notes come just before the beat, and the final D1–D2 tremolo is played out in sixteenths. - **Variation** : the timing wanders slowly by a few milliseconds, and velocities and releases vary a little from note to note. The randomness is seeded, so every build is the same. - **Repeats** : both are taken (bars 141–172 and 391–422), with their first and second endings: 603 bars, about 7½ minutes. The code (`brf.py`, `perform.py`, `render.swift`) is under the [MIT license](https://github.com/chris-mccoy/gottschalk-tarantelle/blob/main/LICENSE-MIT). The braille transcription in `espadero.brf` is by Hu Haipeng, for the Braille Orchestra and Open Braille Music projects ([brailleorch.org](http://www.brailleorch.org)), published on [IMSLP](https://imslp.org/wiki/Grande_Tarantelle%2C_Op.67_%28Gottschalk%2C_Louis_Moreau%29) (#933069) under the Creative Commons Attribution-ShareAlike 4.0 license. The MIDI and audio performances are adaptations of it, and they and the rest of the repository (this README included) are shared under the same license: [CC BY-SA 4.0](https://github.com/chris-mccoy/gottschalk-tarantelle/blob/main/LICENSE-CC-BY-SA-4.0). The Ditson print of 1874 that the transcription follows, and Gottschalk's and Espadero's music, are in the public domain.