Product · 2026 · Dovire product
SongSheet
A chord-sheet arranger and presenter for musicians, with real music theory under the hood: from transposition to per-instrument voicings.
Problem
Most chord apps stop at shifting chord names up and down. Working musicians need more: correct enharmonics in every key, capo and voicing decisions per instrument, and a presentation view that reads clearly from a music stand mid-song.
Approach
We built an arrangement engine that treats music theory as a first-class domain: keys, modes, harmony and voicing rules are modelled explicitly and pinned down by 600+ unit tests, so a transposition is a musical decision rather than a string replacement. A presenter mode renders clean, stage-readable sheets.
Outcome
Arrangements stay musically correct through key changes and instrument switches, and the engine's test suite means new features can't quietly break the theory.
More work
Related projects.
More of what we've built and shipped.
