Contrapunctus — Music Theory Analysis, Exercises & Classroom Tools

Contrapunctus — Compose with clarityBuilt for theory students, educators, and the music theory community.A music theory platform with real-time harmonic analysis, part-writing feedback, and non-chord tone detection. Join a community of theory enthusiasts solving exercises, or use the classroom tools to author assignments and track student progress.Practice with the communityCreate exercises, solve others' challenges, earn points, and climb the ranks.Designed for the theory classroomSet up a class, share an invite link, author custom exercises, and track student progress from a single gradebook view.Powered by real-time analysis

Real-Time Harmonic Analysis — Roman numerals and chord types appear instantly as you write.

Part-Writing Error Detection — Catch parallel fifths, voice crossing, spacing errors, and more.

Non-Chord Tone Detection — Passing tones, neighbor tones, and suspensions automatically classified.

Multi-Voice Composition — Write for any number of voices across treble and bass clefs.

Key and Scale Awareness — Analysis adapts to major, minor, and modal contexts.

Music Playback — Listen to your composition with sampled instruments.

Who it's forStudents — Join classes, work through exercises, and practice with the community.Educators — Create classes, author exercises, review submissions, and track completion.Theory Enthusiasts — Challenge yourself with community exercises and climb the ranks.Composers — Sketch ideas with real-time harmonic awareness.Create Free Account | Sign In