Sleeping People is an instrumental rock band from San Diego, California that formed in early 2002. They first started playing live at the end of that year as a trio consisting of Joileah Concepcion (guitar), Kasey Boekholt (guitar) and Brandon Relf (drums), with bassist Kenseth Thibideau joining the group in 2003. In 2005, the band released their self-titled debut album through Temporary Residence records. Around that same time, guitarist Joileah left the band due to relocation, and her friend Amber Coffman replaced her on guitar. With Amber they wrote and recorded 3 tracks that appeared on their second album, Growing. In early 2007, Joileah returned to her former position, and the original lineup resumed. The style of instrumental rock they play is sometimes referred to as math rock, which is characterized by complex, atypical rhythmic structures, stop/start dynamics and angular, dissonant riffs.