viSolfa
100% On-Device AI • iOS 17+

Sight-sing any sheet music with 1 photo.

viSolfa photographs one page of standard sheet music (五线谱) and overlays solfège labels directly onto your original photo. Teacher markings, pencil fingerings, and layout remain 100% intact.

Score_OdeToJoy_D_Major.jpg
D Major (2♯) Movable-Do
Mi
Mi
Fa
Sol
Sol

✨ Original handwritten teacher notes and pencil marks stay untouched under the vector pill layer.

Non-Destructive Sight-Singing

Preserves your score's physical reality.

✕

Traditional OMR (e.g., DomiSol)

Re-engraves the score from scratch into Jianpu or tonic sol-fa.

  • • Erases teacher pencil annotations and fingerings
  • • Destroys original measure layout and spatial muscle memory
  • • Re-engraving errors confuse complex polyphony
✓

The viSolfa Paradigm

Treats your score photo as an augmented document with vector overlays.

  • • 100% of your notes, markings, and stamps remain visible
  • • Toggle movable-do and fixed-do instantly with zero lag
  • • 1-tap manual key override recovers from any lighting glitch

Two Solfège Methodologies

Movable-Do (首调) & Fixed-Do (固定音名)

Movable-Do (首调)

Tonic Follows Key

The tonic pitch of the key signature is always sung as Do (1). Used widely in vocal music, choir rehearsal, and Kodály music education.

Key of G Major (1♯): G = Do, A = Re, F♯ = Ti
Key of F Major (1♭): F = Do, G = Re, B♭ = Fa

Fixed-Do (固定音名)

C = Do Always

C is always Do, regardless of the key signature or clef. Favored by conservatories and instrumentalists (piano, violin, brass), immune to key-signature misreads.

Any Key: C = Do, D = Re, E = Mi, F = Fa, G = Sol
Accidentals: F♯ = Fi (♯4), B♭ = Te (♭7)

Zero Theory Hallucination

Decoupled Perception & Rule Layer

Stage 1: Perception

On-Device Object Detection

Core ML & LiteRT detect staff systems, clef anchors, key signatures, and notehead coordinates.

Stage 2: Deterministic

Pure Music Theory Engine

A 100% deterministic rule engine resolves tonic and scale degrees across all 30 Major/Minor keys.

Transparent Dual-Entity Model

Three Clear Tiers

Foundation 501(c)(3)

Community

Free / 0 Ads (No UBIT)
  • ✓ 20 page scans / month
  • ✓ Movable-Do (首调) mode
  • ✓ 100% local, no account required
  • • Subtle watermark on exported scores
Community Download
VI AI Inc. Ad-Supported

Pro

Free / Google AdMob
  • ✓ 100 page scans / month
  • ✓ Both Movable-Do & Fixed-Do
  • ✓ No watermark on exports
  • ✓ Optional cloud synchronization
Pro Download
Best Value
VI AI Inc. Subscription

Max

$4.99 / mo ($39.99/yr)
  • ✓ Unlimited score scans
  • ✓ 100% Ad-Free experience
  • ✓ Handwritten score recognition
  • ✓ PDF & MusicXML vector export
  • ✓ Classroom & multi-user license
Unlock Max

Ready to master your sight-singing?

Join our private iOS TestFlight build or explore the open-source music theory engine on GitHub.