How does the circle of fifths work? A plain-English guide to the circle of fifths — what it is, how to read it, and why it makes key signatures, chord progressions, and modulation easier to understand. How to remember base triads Memorise the four basic triads — major, minor, diminished, augmented — by the interval pattern between their three notes, not by rote memorisation of every chord. How to read a key signature A practical guide to identifying any key signature in seconds — the order of sharps and flats, the two simple rules that decode them, and the shortcuts that make sight-reading effortless. Major vs. minor: what makes them sound different Major sounds bright. Minor sounds dark. But why? A look at the one interval that separates them, the cultural conditioning behind "happy" and "sad," and the moments where the rule breaks. Etudle: a daily music theory puzzle (like Wordle, but for chords and keys) Etudle is a free daily music theory puzzle. 15 cards, 3 rounds, same puzzle worldwide, fresh every day at midnight UTC. Like Wordle, but for chords, key signatures, and intervals.