"in c" has no set duration; performances can last as little as fifteen minutes or as long as several hours, although riley indicates "performances normally average between 45 minutes and an hour and a half." the number of performers may also vary between any two performances. the original recording of the piece was created by 11 musicians (although, through overdubbing, several dozen instruments were utilized), while a performance in 2006 at the walt disney concert hall featured 124 musicians.