
Timing and rhythm are vital to all forms of music. Without this the sound becomes unformulated and the musicians cannot play in unison.
The tempo of music is measured in BPM, or Beats Per Minute. 60 BPM is 1 beat a second.
Sometimes this is written at the beginning of the music and is called a Metronome marking.
Tempo and stylistic feel is often indicated in classical music by Italian terminology