The Mars Volta is an American rock group formed in 2001 by guitarist Omar A. Rodriguez-Lopez and vocalist Cedric Bixler Zavala. They incorporate various influences including post-hardcore, jazz fusion, psychedelia, funk and latin/salsa into their sound. They are characterized for their energetic and improvisational live shows, as well as their concept-based studio albums.

The roots of The Mars Volta are found in the band At the Drive-In. Cedric Bixler-Zavala and Omar Rodriguez-Lopez, both members of At the Drive-In, formed an experimental, dub reggae-influenced side project called De Facto, which featured Bixler-Zavala on drums, Rodriguez-Lopez on bass, Isaiah Owens (AKA “Ikey”) on keyboards, and Jeremy Michael Ward on vocals, loops and sound effects.

Due to creative differences and discomfort with mainstream success, Rodriguez-Lopez and Bixler-Zavala quit At the Drive-In in 2001. The remaining members of At the Drive-In formed Sparta. By the time bassist Eva Gardner joined De Facto, they had changed their name to The Mars Volta. During 2001, the band recorded two songs with former-Laddio Bolocko drummer Blake Fleming and producer Alex Newport, which became their first demo. The lineup for their first public show at Chain Reaction in Anaheim, California was Rodriguez-Lopez, Bixler-Zavala, Owens, Gardner, Ward, and drummer Jon Theodore. This lineup recorded three more tracks with Alex Newport, which became the EP Tremulant, released as a limited edition in early 2002.