Rhythm is the duration of pitches or tones and silence. Rhythms are dictated by a combination of notes at a certain speed or tempo, but they work within a framework called meter.
Meter refers to the regularly recurring patterns and accents such as bars and beats. The performer expresses meter, and listeners expect it even if they don’t understand the concept. Musicians represent meter by using a pair of numbers or a special symbol at the beginning of a score. When the meter appears as numbers, the number on top means the number of beats that will appear in each of the measures; the number at the bottom reports which type of note gets the beat.