expert · LCM = 28
Four against seven — deeply hypnotic but rarely encountered outside notation.
Pattern — 28 subdivisions per cycle
Mute one layer to focus on the other. LCM = 28 subdivisions per cycle.
About 4:7
4:7 has an LCM of 28 and creates 11 distinct attack points. The cycle is very long, and the two layers feel almost independent for long stretches before briefly aligning. Extremely difficult to feel intuitively — most performers use subdivision counting rather than ear training to navigate it.
LCM of 4 and 7 is 28 subdivisions. This is one of the longer cycles among common polyrhythms.
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
Xenakis Percussion Works
Iannis Xenakis
Expert-level polyrhythm notation
Spectralist Compositions
Various
Ratio-derived rhythmic layers