Compound Time Signatures (6/8, 9/8, 12/8)
Time signatures where each beat divides into three — the lilting swing behind jigs and many ballads.
This chapter has moved. When the Music Theory track was rewritten (Aug 2026) to match the current Theory Packs, compound time moved from Grade 3 to Grade 2. Head to Compound Time, Grouping & Triplets in Grade 2 for the current version, with an updated quiz.
Explainer
In compound time, each main beat divides naturally into THREE, not two.
6/8 has two main beats per bar (each worth a dotted crotchet = 3 quavers). 9/8 has three main beats. 12/8 has four main beats.
The bottom number (8) means the quaver is the basic unit being counted, but the FEEL is in groups of three quavers per beat — giving compound time its rolling, lilting feel.
Worked examples
6/8 — two beats per bar
Two groups of three quavers: ONE-and-a, TWO-and-a.
9/8 — three beats per bar
Three groups of three quavers: ONE-and-a, TWO-and-a, THREE-and-a.
12/8 — four beats per bar
Four groups of three quavers — the same rolling feel as 6/8, just twice as long.