Question: Big Sir is a band that includes which bass guitarist, a Mexican-American musician, best known as the longtime bassist of Racer X and The Mars Volta?
Context: Juan Alderete de la Peña (born September 5, 1963) is a Mexican-American musician, best known as the longtime bassist of Racer X and The Mars Volta. Cedric Bixler-Zavala (born November 4, 1974 in Redwood City, California) is a Grammy Award-winning American musician known for his work as frontman and lyricist of the progressive rock band The Mars Volta, and as frontman and occasional guitarist of the post-hardcore group At the Drive-In.  Currently he is a singer in the band Antemasque, and also sings and plays guitar in his band Zavalaz.  He has also played drums for a number of acts, including the dub act De Facto and more recently Big Sir and Anywhere. Big Sir is a band that includes the bass guitarist Juan Alderete (The Mars Volta and Racer X) and the singer Lisa Papineau. Before Gardens After Gardens is the third album by Big Sir.  The album features contributions by The Mars Volta’s Cedric Bixler-Zavala and Deantoni Parks, Rx Bandits’ Matt Embree and Steve Choi, bassist Jonathan Hischke and Beastie Boys producer Money Mark. Und Die Scheiße Ändert Sich Immer (German for "And the Shit Is Always Changing") is the second album by Big Sir, which includes The Mars Volta bassist, Juan Alderete, and Lisa Papineau of Air and M83. Cizaña de los Amores is the seventeenth studio album by Omar Rodríguez-López as a solo artist.  It was released on October 18, 2010 on CD and vinyl by Rodriguez Lopez Productions on Koncurrent in Europe, then November 18 through the US hello merchandise store.  It is the first collaboration between Omar and vocalist Lisa Papineau, who had previously worked with The Mars Volta bandmate Juan Alderete in their band Big Sir.  This record features the song "Victimas del Cielo" in studio form, having first been released on the live album "Los Sueños de un Hígado". David Elitch (a.k.a. Dave Elitch) is an American musician best known for his work with the American progressive rock band The Mars Volta.  David Elitch moved from Sebastopol, California to Los Angeles and later joined hard rock band Daughters of Mara.  In 2007 Daughters of Mara recorded their debut album "I Am Destroyer" with GGGarth Richardson on Virgin/Capitol Records.  In Oct. 2009, Dave made his live debut with The Mars Volta in Oslo and completed the second leg of the Octahedron Tour, touring in Europe, Australia and South America.  Dave Elitch has since worked with Miley Cyrus, M83, Justin Timberlake, Susanne Sundfør, Big Sir, Juliette Lewis, Crash Kings and Vicky Cryer as well as many others.  Dave also conducts masterclass lectures and teaches privately in Los Angeles; one notable student is comedian Bill Burr. Los Dregtones was a band from El Paso, Texas, led by Cedric Bixler-Zavala (vocals/drums), Ralph Jasso (guitar) and Jimmy Hernandez (bass).  The line-up changed multiple times with Julio Venegas playing bass for a long duration while Hernandez was off at music school at the Atlanta Institute of Music in Atlanta, GA.  Other members included Luis Prieto (Percussion), Brooks Miller (trumpet), Adam Young (drums), and Andrew McCoi (drums).  In 1994, they released a demo recorded at Rosewood Studios by Mike Majors (produced by Sparta), titled "Five Song Alibi".  The style of the album was not unlike what lead singer Cedric Bixler would later perform with The Mars Volta; psychedelic rock, with hints of salsa, reggae, and occasional Led Zeppelin-esque guitar riffs, with punk rock.  The cover and insert art was drawn by Julio Venegas, which features a six armed serpent women with a third eye and long ugly hair, and a symbol on the end of its tail that would later be used by Cedric and Omar Rodríguez-López on The Mars Volta's stickers, shirts, and other merchandise.  Guitarist Ralph Jasso would later play bass briefly for The Mars Volta. Pablo J. Hinojos-Gonzalez (born July 17, 1975), also known as Paul Hinojos, is an American musician best known as the bass guitarist for At The Drive In, and former touring member of The Mars Volta.  He is also a former guitarist of Sparta. Antemasque (stylized as ANTEMASQUE) is an American rock band formed in 2014 by former members of At the Drive-In and The Mars Volta, Omar Rodríguez-López and Cedric Bixler-Zavala.  Their first album featured Red Hot Chili Peppers's Flea on bass and Dave Elitch on drums.  Both Flea and Elitch had previously played with The Mars Volta.  Omar's brother Marfred Rodríguez-López (formerly of Zechs Marquise) eventually joined as a permanent bassist with Blink-182 member Travis Barker taking over drumming duties.
Answer: Juan Alderete