海岛扫弦型（D-DU-UDU）

What the letters mean

D is a downstroke, U is an upstroke, and the hyphen is a silent eighth note — a moment where your hand keeps moving but does not touch the strings. So D-DU-UDU is six contacts spread across eight eighth notes, counted 1, 2-and, and-3-and.

The pattern is sometimes printed as D-DU-UDU and sometimes as D-DU-UDU-DU. They are the same thing read at different bar lengths: the first notation assumes one bar of 4/4 per repetition, and the extra DU at the end simply fills the fourth beat.

Why it is the first pattern to learn

Your hand never stops moving. Every strum pattern that sounds difficult is built from this one by removing strokes, and you can only remove a stroke cleanly if the hand keeps swinging through the gap. Practise it with the strings muted by your left hand — a flat palm across all four strings — so you hear only the rhythm.

• Metronome at 60. Play four bars muted, four bars open.
• Say "down, down-up, up-down-up" out loud for the first week.
• Once it is automatic, drop the metronome and count the bar in your head instead.

The two mistakes everyone makes

Accelerating on the upstrokes. The upstroke is lighter than the downstroke, not faster. If your tempo drifts, you are pushing the up.

Changing chords on beat four. The change belongs on beat one of the next bar. If you move early you will clip the previous chord, and the pattern will suddenly sound rushed even though the tempo has not changed.

Where it fits

This pattern carries most 4/4 sing-along material at 70-110 bpm. Above 110 it starts to feel heavy; that is when you move to the campfire downstrum with accents, or a Calypso swing.