Cavaquinho Hero

See it live at: https://bigodines.github.io/cavaquinho_hero/

A music theory toolkit for cavaquininstas learning and practicing chords, scales, and harmonic fields.

Features

• Chord Generator: Generate triads and tetrads (7th chords) for any note
• Harmonic Field Explorer: Explore major and minor harmonic fields with diatonic chords, dominants, ii-V-I progressions, and substitutions
• Chord Visualization: View chord shapes on a fretboard (beta)

Getting Started

Prerequisites

• Node.js 18 or later
• npm or yarn

Installation

npm install

Development

# Run development server
make run
# or
npm run dev

Open http://localhost:3000 with your browser to see the result.

Available Commands

make help         # Show all available commands
make run          # Run development server
make build        # Build for production
make test         # Run tests
make lint         # Run linter
make type-check   # Run TypeScript type check (via npm run type-check)

Testing

npm test          # Run tests once
npm test -- --watch  # Run tests in watch mode

Project Structure

├── components/     # React components
│   ├── Header/     # Navigation header
│   ├── ChordTable/ # Chord display table
│   ├── HarmonicField/ # Harmonic field explorer
│   └── Chordz/     # Chord visualization SVG components
├── lib/            # Core music theory modules
│   ├── scales.ts   # Scale generation (major, harmonic minor)
│   ├── chords.ts   # Chord construction (triads, tetrads)
│   ├── tonality.ts # Harmonic fields and progressions
│   └── fretboard.ts # Fretboard representation
├── pages/          # Next.js pages
│   ├── index.tsx   # Home page
│   ├── chords.tsx  # Chord generator
│   ├── harmonic_field.tsx # Harmonic field explorer
│   └── about.tsx   # About page
└── styles/         # Global styles

Music Theory Modules

Scales (lib/scales.ts)

• major(root) - Generate major scale
• harmonicMinor(root) - Generate harmonic minor scale
• isValidNote(note) - Validate note
• noteAdd(note, semitones) - Transpose a note
• enharmony(from, to) - Find enharmonic equivalent

Chords (lib/chords.ts)

• Triads: majorTriad, minorTriad, augmentedTriad, diminishedTriad
• Tetrads: sevenTetrad, sevenMajorTetrad, minorSevenTetrad, etc.
• Sixth chords: sixthTetrad, minorSixthTetrad

Tonality (lib/tonality.ts)

• majorDiatonicScale(root) - Major harmonic field
• harmonicMinorDiatonicScale(root) - Minor harmonic field
• dominantChord(chord) - Find V chord
• iiChord(chord) - Find ii chord for ii-V-I
• subV(chord) - Find tritone substitution

License

AGPL