Melody scores for YuE2

YuE2 sings lyrics over a melody score written in a strict native ABC dialect, stored in the music work's abc field. Call get_work first: settings.abc is the current score, text the style, settings.lyrics the lyrics. Only music works whose modelId starts with yue2- use it.

Native dialect, all required

• Header lines exactly in this order: X:1 / T: (blank) / M:<n>/<d> / L:1/<power of two> (keep the source value, usually 1/32) / Q:1/4=<integer BPM> / V: Vocal clef=treble name="Vocal Melody" snm="Vocal" / V: Ins clef=treble name="Ins Melody" snm="Inst." / K:<major or minor key such as G, Bb, F#m>.
• Music is written in groups of 1 to 4 measures: a V: Vocal line and its music line, then a V: Ins line and its music line with the same number of measures. Each music line ends with |.
• Sections are comment lines such as %% verse, %% chorus, %% bridge, %% interlude before a group.
• Both voices are monophonic melodies. Ins carries instrumental themes or solos and rests while the vocal sings; it is not a chord staff.
• Chord symbols are quoted and only in Vocal, also while Vocal rests: "C", "Am7", "F#m7/C#". Allowed qualities: major (no suffix), m, dim, aug, 7, maj7, m7, dim7, m7b5, sus4, sus2, 6, m6, 7sus4, m(maj7); optional /bass.
• With L:1/32 a 4/4 measure holds exactly 32 units (3/4 and 6/8 hold 24). Duration multipliers are only 1,2,3,4,6,8,12,16,24,32,48; write other lengths as tied notes like C8-C2. z is a rest; Z, Z2, Z3, Z4 are whole resting measures.
• c is an octave above C, c' above c, C, below C. ^ sharp, _ flat, = natural; accidentals last to the barline and apply to the same letter in every octave. The key signature applies to unmarked notes.
• A tie (-) joins equal pitches; a chord change inside a held note splits it with a tie: "C"E16-"Am7"E16. A tie never enters a rest and the score never ends on a tie.
• Not allowed: lyric w: lines, tuplets, grace notes, bracketed note stacks, slurs, repeat signs, decorations, %%% directives, extra voices.

How to write or edit

• With no score yet: one section comment per lyric section, a singable vocal line with chords, short instrumental themes in Ins between vocal phrases.
• When editing, change only what the request asks for and keep everything else note for note: other sections, the other voice, chords, tempo, key and meter. Keep section comments and bar grouping.
• Keep vocal phrases singable for the lyrics: roughly one note per syllable, held notes on long vowels, rests where lines breathe.
• Check that every measure adds up to the meter before applying.
• When the request changes the arrangement feel (genre, instruments, tempo, vocal character), also update the style (text) in English tags.

Apply with one update_work {"id", "abc": } (plus "text" when the style changes). If it is rejected, the error names the measure and the problem: fix exactly that and update again. Tell the user in one sentence what changed.