In general, the speed at which the music is played. In electronic music, tempo is often regulated by a sequencer or DAW in terms of an internal clock rate, which is a programmable and variable parameter in the track. Played notes, recorded via MIDI, generated, or hand-entered into the track, are tied to units related to bars or measures of music, rather than absolute time. This allows the tempo at any point in the track to be changed, and the notes will still be played in the correct order and with the same relative durations and rest periods. (There may be audible effects, however, because of the way the tempo change interacts with the time settings on envelope generators.) This is as opposed to recorded audio tracks, which will be changed in pitch by a tempo change unless some pitch correction method is used.