An
indoor percussion ensemble or
indoor drumline consists of the
marching percussion (or
battery) and front ensemble (
pit or
frontline) sections of a
marching band or
drum corps. The only exceptions are in concert divisions (e.g. Percussion Scholastic Concert Open) where the marching line is absent and the ensemble consists entirely of a pit. Indoor Percussion marries elements of music performance, marching, and
theater; thus, the activity is often referred to as
percussion theater. Although most indoor percussion ensembles are affiliated with high schools, there are also many independent groups that draw participants from a large area. Independent groups typically start rehearsing in October, while high school groups typically start after their Fall marching band season ends. Because of this, the activity is often called
Winter Percussion or
Winterline.