Para-diddle — the word is the rhythm, and the rhythm is a lever.
The Rudiment
The single paradiddle is the most important hybrid rudiment and arguably the most useful pattern a drummer can own. It combines two single strokes with one double — "para" (two singles) plus "diddle" (a double) — into a four-note cell whose great virtue is that it flips the lead hand every time it repeats. Start on the right and the pattern hands you the left; this built-in alternation lets you distribute accents and melodies around the kit in ways pure singles or doubles never could.
Sticking
The standard sticking is RLRR LRLL, with an accent on the first note of each group. The right-lead half (RLRR) ends on a right double, which sets up the left-lead half (LRLL) — so the accent naturally moves hand to hand every four notes. Counted as sixteenth notes, one paradiddle fills a beat, with the accent landing on the pulse.
How to Play
Play the accented first note as a full stroke, keep the two following notes low, and let the closing double rebound evenly. The magic is dynamic contrast: the accent should sing while the diddle stays quiet, so the pattern breathes rather than sounding like flat sixteenths. Practice it open and slow to balance the accent against the taps, then bring it up to speed keeping the hands relaxed.
In Practice
The single paradiddle is everywhere — funk and rock grooves, linear fills, jazz comping, and any moment you want a smooth accent to travel across drums and cymbals. It is the root of the Double Paradiddle, Triple Paradiddle, and Single Paradiddle-Diddle.