Chord progressions
A chord progression is the order chords come in, repeated bar after bar under a song. A handful of them carry most of pop, and each has a name in Roman numerals so it can be played in any key. Each card below plays: pick a key, pick a style, press play.
Learn harmony by ear
Mood without music theory. Chords, major and minor, the key, home and away, and colour notes, each with something to play. Unit 1 is free with a Google sign-in.
Pick up where you left off
Carry on with Unit 1; chords come in Unit 4: Harmony.
What the Roman numerals mean
A key has seven notes, and a chord can be built on each of them. The numerals count those chords from the key’s home note: I is the chord on the first note, IV on the fourth, V on the fifth, vi on the sixth. Capital numerals are major chords, small ones minor, so in C major the seven are C (I), Dm (ii), Em (iii), F (IV), G (V), Am (vi) and B° (vii°).
Naming chords by number means a progression is the same shape in every key: I–V–vi–IV is C, G, Am, F in C major and G, D, Em, C in G major. Singers pick the key that suits their voice; the progression doesn’t change. The key selector on each card does exactly that.
Which progression you pick matters less than you might think. The styles on each page prove it: the same four chords are a ballad with piano on the beat, house with stabs off the beat, and trap with a long dark pad, because the drums, the bass rhythm and the sounds carry the genre.