Serpa

Write a second voice against a cantus firmus and get every rule checked. Serpa is a tutor for written counterpoint. You work against a fixed melody, the cantus firmus, and write a second voice above or below it on a two-staff canvas. The app 📱 checks your work against the rules and tells you what to fix. Tap 👆 a slot on the staff to place a note 📝. Drag ✋ it up or down to change its pitch. Press and hold a note to add a sharp, flat or natural, or to delete it. After every change the app 📱 re-checks both voices. Each problem shows as a coloured badge above its bar. Tap a badge to read which rule it is, what interval or motion caused it and why it matters. "Show me" marks the offending motion on the staff. What you can do in Serpa: - Follow a winding path of 30 exercises across five chambers, from note 📝 against note to florid counterpoint - Work in six modes: Dorian, Phrygian, Lydian, Mixolydian, Aeolian and Ionian - Open the hint drawer for species tips and the cadence formula for the mode - Submit an exercise to get a score 🔢, up to three stars and notes 📝 on each slip - Write your own cantus firmus in the Studio and practise against it - Browse the Rulebook, where each rule has a looping before-and-after diagram 📊 - Track progress 📈 in the Ledger with a score 🔢 trend, your most frequent slips and the seals you have earned - Choose between two notation skins and set how much help the hints give The app 📱 does not play ▶️ sound. It is a checker for written lines. Everything runs on your device. You need no account, and your progress 📈 stays with you. Use Serpa to learn 📖 species counterpoint step by step, or to check ✅ a line you wrote yourself.