Rhythm is a word from the Greek, meaning 'something that repeats regularly'. In the case of music this is the pattern of sounds and silences (the time between drum beats, for example).

People have their own internal rhythm, as determined, for example, by a heartbeat or pulse. So this makes us sensitive to other patterns of beats (rhythms). What a percussion rhythm does is to act on our brains that already have built-in rhythms, like pulses.

Once we are aware of a rhythm, our brains anticipate it continuing. It is almost like a clock going tick-tock.

Listen for the rhythm produced by the drums. What else can you hear making the rhythm?