A drummer marks beats two and four with the snare. A ukulele marks them with the chunk: a downstroke where the side of the strumming hand lands on the strings in the same motion that strikes them, so the chord dies instantly into a percussive “chk”. It is the single technique that most separates a played uke from a strummed one — one player suddenly sounds like a rhythm section.
The motion
Strum down and let the fleshy edge of your palm (the karate-chop side, below the little finger) land on the strings a split second after — or effectively with — the stroke. The strings sound for a millisecond and are muted; what survives is attack, no ring. Two faults account for nearly every bad chunk: landing the palm before the strings are struck (silence instead of “chk” — let the fingers lead by a hair), and bouncing the palm back off (which lets the chord bloom back in — leave the palm resting until the next stroke needs the strings).
The drills
Written one column per step, stroke line above the tab: D down, U up, x the chunk, · a silent swing. The first drill is quarters only — strum, chunk, strum, chunk — which is the backbeat skeleton. The second slips the upstroke in right after the chunk, while the strings are still muted, so the up clicks instead of rings; that mute-then-up is the sound of nearly every campfire uke groove. The third runs the backbeat across a C-to-F change, because the chunk’s hidden gift is time: beats two and four need no left hand at all, which is exactly when your fingers travel.
Using it in songs
Start by replacing beat three’s downstroke in the workhorse pattern with nothing at all, and beat two’s with a chunk — most songs want less strumming and more groove than beginners give them. The chunk also scales down gracefully: at low volume it becomes a soft tick that keeps time under fingerpicked verses. Pair it with the patterns from strumming patterns, keep the pendulum honest with the metronome, and when the backbeat feels inevitable, the daily drills page will keep it maintained. The show-off sibling — the fan stroke — decorates exactly the beats the chunk leaves empty.