Cornerstone Percussion, a competitive indoor drumline from San Diego, California, was founded in 2010. Indoor percussion combines elements of music performance, marching and theater. The activity is often referred to as percussion theater and the sport of music.
Competitions are held during January-April each year, in addition to multiple opportunities to perform at community events and shows. Winter Guard International (WGI) Percussion Contest Rules dictate that participants are composed of members between ages 14 and 22.

Cornerstone Percussion competes in Independent A Class in Winter Guard International (WGI), Southern California Percussion Alliance (SCPA) and American Drum Line Association (WGASC/ADLA). We are dedicated to giving percussionists an opportunity to perform in an indoor percussion ensemble while still being able to manage academic, work and family responsibilities.

They are percussionists at high schools with no winter drumline...they are percussionists who have graduated and still want to be part of the activity...they are band members who want to do winter drumline and try out front ensemble or cymbals...they are from all over Southern California...they are musicians who want to gain experience to join drum corps or open/world level WGI groups. Sound like you? Come join us!