Harmonic progressions exist when one harmony proceeds to the next. The speed and complexity of this progression contributes to both the energy and character of the music. Given the same tempo, a harmonic progression that is slow (every four beats) will make the music more relaxed than one that is faster (every two beats). Harmonic progressions in most popular music are often fairly regular, but there are exceptions. Classical music and Jazz tend to be more adventurous in the harmonic progressions. Of course, there are exceptions in all genres.