MusicReason

Scales, Keys, Intervals, and Notation

Pitch collections, keys, and intervals

This category owns questions about pitch relationships themselves: what notes make up a scale or mode, what a key signature implies, how two pitches relate as an interval, and how any of that should be spelled on paper. It excludes performance-practice tools and live audio inference, which live under Ear Training and Playable Exploration and Local Audio Analysis and Recognition.

Why spelling is treated as data, not decoration

A pitch class alone (just "the note two semitones above C") throws away information a musician actually needs: whether that note is written as a D or some other enharmonic spelling changes how it reads in context. Every tool here keeps a spelled note's letter, accidental, and octave through the whole calculation and only reduces to a bare pitch class internally, never as the user-facing result. The Scale Explorer and Key Signature Explorer anchor this category in the current foundation release: the first builds and plays any supported scale formula from a chosen tonic, and the second shows exactly what a key signature's accidentals are and how it relates to its relative major or minor.

Tools in this category