Double time
Doubletime (also Double Time or Doublebeat ) is a common term in music for a passage that is played at double speed. The opposite of doubletime is halftime when playing at half the speed.
Double time in jazz / rock / pop
In jazz , rock and pop , the double time denotes a doubled speed of the basic beat (beats). The tempo does not change, but the rhythm pattern is doubled within its bar structure by using correspondingly shorter note values . The progression of harmony , the chord changes , happen at the same speed as before. The change to double time is agreed or spontaneously among the musicians, so it is not notated and, especially in improvisational parts of the piece, depends on the character of the improvisation. Usually the speed is doubled at the beginning of a form , but it can also happen in the middle of the piece, when a musician, usually the soloist, gives it and the others follow. After a few passes through the form, the original speed is often taken over again. Composed music makes less use of doubletime than improvised music.
Double time in rap
In rap music , a text passage in the "normal" tempo consists of 16 syllables per measure. With double time, however, there are 24 syllables per measure.