intermediate · LCM = 12
Six against four — equivalent to 3:2 doubled. The root of swing feel.
Pattern — 12 subdivisions per cycle
Mute one layer to focus on the other. LCM = 12 subdivisions per cycle.
About 6:4
6:4 is 3:2 at double density. Six notes against four — the 6-layer creates triplet subdivisions against the straight 4-layer. This is exactly what jazz swing is: the melody phrases in groups of 3 against a 4/4 rhythmic framework. The LCM is 12.
LCM of 6 and 4 is 12, same as 3:4. It's 3:2 in double time.
Verbal mnemonic
"nice cup of tea"
Practice levels
Hear the combined pattern with visual highlighting
Start →Identify which ratio you're hearing from a short list
Start →Identify with one layer muted — hear the implied pattern
Start →Identify ratio, muted layer, and tempo simultaneously
Start →Examples in music
Jazz Standards
Various
Swing feel is 6:4 in practice
Blues
Various
Triplet-over-4 is ubiquitous
Gospel Music
Various
Triplet patterns over 4/4
Born to Run
Bruce Springsteen
6:4 accents in the arrangement