LilyPond: Espresso Rag hand crossing, by gpt-6-luna
gpt-6-luna · round 7 of 7 · seed 2$0.01SVGMP3MIDIrag.ly
rag.ly · 67 lines
\version "2.24.0"
\header {
  title = "Espresso Rag"
  subtitle = "A café piano rag — L.H. crosses over R.H. in bars 9–12"
  composer = ""
  tagline = ##f
}

rightHand = \relative c'' {
  \clef treble
  \key f \major
  \time 2/4
  \tempo "Bright, with a little swing" 4 = 116
  \voiceOne
  a8 c'8 f,8 a8 | g8 bes8 e,8 g8 |
  f8 a8 d,8 f8 | e8 g8 cis,8 e8 |
  d8 f8 bes,8 d8 | c8 e8 a,8 c8 |
  bes8 d8 g,8 bes8 | a8 c8 f,8 a8 |
  c'8 a8 f8 a8 | d8 bes8 g8 bes8 |
  c8 a8 f8 a8 | e8 c8 a8 c8 |
  f8 a8 c'8 a8 | e8 g8 bes8 g8 |
  d8 f8 a8 f8 | c8 e8 g8 c8 |
  \bar "|."
}

leftHand = \fixed c {
  \clef bass
  \key f \major
  \time 2/4
  \voiceTwo
  f,4 <c' f a>4 | c,4 <g' c e>4 |
  bes,4 <f' bes d>4 | f,4 <c' f a>4 |
  g,4 <d' g bes>4 | c,4 <g' c e>4 |
  f,4 <c' f a>4 | c,4 <g' c e>4 |
  R2 | R2 | R2 | R2 |
  f,4 <c' f a>4 | c,4 <g' c e>4 |
  bes,4 <f' bes d>4 | f,4 <c' f a>4 |
  \bar "|."
}

crossHand = \relative c'' {
  \key f \major
  \time 2/4
  \voiceTwo
  s2 | s2 | s2 | s2 | s2 | s2 | s2 | s2 |
  \transpose c c'' {
    <c f a>4 <a c f>4 | <d g bes>4 <bes d g>4 |
    <c f a>4 <a c f>4 | <e a c>4 <c e a>4 |
  }
  s2 | s2 | s2 | s2 |
}

\score {
  \new PianoStaff \with { instrumentName = "Piano" } <<
    \new Staff = "up" <<
      \new Voice = "right" { \rightHand }
      \new Voice = "cross" { \crossHand }
    >>
    \new Staff = "down" <<
      \new Voice = "left" { \leftHand }
    >>
  >>
  \layout {
    \context { \Score \override BarNumber.break-visibility = ##(#f #t #t) }
  }
}
round 1 of 7
Espresso Rag, with the left hand crossing over, by GPT-6 Luna, the render after round 1
1234567What the model saw after each round. The picture above is the round that was scored, round 7.
gallery/Espresso Rag, with the left hand crossing over/GPT-6 Luna, run 2

Espresso Rag, with the left hand crossing over: GPT-6 Luna

modelopenai/gpt-6-lunatasklilypond-espresso-rag@v1, checks c1, harness h1date2026-10-05rounds7 of 8 allowed, 12 minutes on the clockcost$0.0106thinkingmediumtokens224,971 in, 13,550 out, of which 9,983 reasoningtime3 min 16 sfailedLeft hand crosses: false, relation misencoded, critical, 4 of the 4 crossing bars without the left hand above, its note said this very thing was right · Crossing marked: incomplete, annotation missing, minor, 0 of 2 marks, the crossing and its release, its note said nothing either way
Piano staffdecided by a number, from the filepass
Sixteen barsdecided by a number, from the filepass
Left hand crossesdecided by a number, from the filefail
Right hand keeps goingdecided by a number, from the filepass
Crossing markeddecided by a number, from the filefail
Stems apartdecided by a number, from the filepass

There is no post about this one, since only some results need one, so the picture, the source and the scoring are here instead.

its other runs
Espresso Rag, with the left hand crossing over, by GPT-6 Luna, run 1run 1 · 2r · $0.0028Espresso Rag, with the left hand crossing over, by GPT-6 Luna, run 3run 3 · 2r · $0.0032
same prompt, other modelsall 12 runs on Espresso Rag, with the left hand crossing over →
the prompt it was given
Write, in LilyPond, 16 bars of café piano music called "Espresso Rag" in which the left hand crosses over the right hand for bars 9 to 12.
Frozen at v1. This model got this and nothing else.
ground truth

LilyPond's own record of every note: its hand, staff, bar, pitch and stem, read while the file is engraved. A voice belongs to the hand whose staff it starts on, unless its notes are labelled with a hand's name. The script was written after hearing Sol's and Pareto's runs, so Luna was its first fair test. How good the music sounds is rated by ear. How it is scored, and this run's files on GitHub.