Build a groove — the backbeat
iBoom, CLAP, boom-boom, CLAP. Turn on the lights and build the beat every song is made of.
for teachers: fractions of a bar · the backbeat · subdivisionOpen →
Never sat behind a kit? Start with the big button — the rock beat, one limb at a time. Then take your hands to stick control: singles, doubles and the paradiddle.
five voices, one groove · the math & physics of rhythm
A skin, a snare and a cymbal each shake in a completely different way — a thud, a crack, a shimmer. Tap them, learn what each one does, build a beat, and find out why a drum can't play a tune but owns time itself.
plate viii · tap any part to play it
meet the kit
learn to play · learn the science
Boom, CLAP, boom-boom, CLAP. Turn on the lights and build the beat every song is made of.
Why can't you play 'Happy Birthday' on a drum? The answer is how a skin shakes.
Three in one hand, two in the other. Find out exactly where they crash into each other.
Rhythm is fractions of time — slice a bar in the Rhythm lab → or bring the kit to a class with the school workshops →
the maths & physics of this instrument
Treating a kit as one thing is the mistake. The kick is a proportion sum, the snare is controlled randomness, a cymbal is a decay curve, the toms are a sequence, and the timpani breaks the rule all four of the others obey. And because none of them can carry a tune, percussion took the other half of music instead — time, which is pure arithmetic.
Inverse proportion · the reciprocal graph
Across drums of the same build, diameter × pitch stays roughly constant: 22 × 60, 16 × 85, 12 × 145 all land near 1470. So f ≈ 1470 ÷ d.
A rack of toms is a reciprocal graph you can hit, with one real object standing on every point.
open it →
Exponential decay · logarithms
Its loudness follows A = A₀ × 2^(−t ÷ t½). It never stops at a moment you could point to — it keeps giving away the same fraction of what's left.
The same curve as a radioactive atom, happening slowly enough to hear the whole way down.
open it →
Ratios that aren't whole numbers
A string's parts are 1 : 2 : 3 : 4. A circular skin's are 1 : 1.59 : 2.14 : 2.30. Nothing lines up, so the ear hears a thud instead of a note.
One instrument where the failure to be whole numbers is the entire point.
open it →
Lowest common multiple · highest common factor
Three in one hand against two in the other needs a six-tick grid — LCM(3,2) = 6 — and they land together gcd(3,2) = 1 time a bar.
The only place a child feels a lowest common multiple in their body instead of finding it on paper.
open it →