15.4 · Advanced Rhythm

Bigger ratios

3 against 2 you can count. Push the numbers up and counting stops working: the two lines stay perfectly steady, but their meetings get so rare that the pattern reads as texture. Same rule as before, just a longer cycle.

Past the classics

Each pair meets only on the downbeat. The closer the counts, the more the lines sound like one rhythm slipping out of phase.

Close counts: it sounds like one line slowly slipping against the other.
35 shared slots. You stop counting and start hearing a wobble.
One extra hit per cycle: the lines phase like two wipers almost in sync.

13 against 17

Both lines are perfectly even. Their shared grid has 221 slots and they agree on exactly one of them. The ear gives up on the grid and hears rainfall.

This is how composers get shimmer from strict math: nothing is random, but almost nothing repeats within earshot.

Now it's yours

The player loops any counts up to 24, three lines if you want. The practice room puts a ratio on two keys and grades each hand.

Open the polyrhythm player →Train it: the polyrhythm room →

Quiz

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In 13 against 17, how many times per cycle do the two lines land together?

Score 100% on every quiz and game to complete this lesson.Five lines, four spaces →