Noteline — handling chords & two hands

Opening of Beethoven's Moonlight Sonata (illustrative excerpt). The left-hand octave is a held chord (two keys at once); the right hand rolls a broken chord; the melody enters on top. Press play, then try the label modes.

Noteline — Moonlight Sonata, opening (with note names)
Noteline Moonlight Sonata — opening (excerpt)
Left hand (held chord) Right hand (arpeggio) Melody

Prototype rendering is hand-built to prove the interaction; production uses OpenSheetMusicDisplay over real MusicXML (chords, voices, ties, full keyboard). See docs/architecture.md. · Noteline home