Question: What do both Andy Partridge and John Mayer do in their bands as well as writing songs and singing?

Context paragraphs:
Take Away / The Lure of Salvage: Take Away and The Lure of Salvage are two sides of a single LP containing dub versions of XTC tracks released under the moniker Mr. Partridge, a pseudonym for Andy Partridge.  It was released on February 29, 1980 on Virgin Records.

John Mayer: John Clayton Mayer ( ; born October 16, 1977) is an American singer-songwriter, guitarist, and producer.  He was born in Bridgeport, Connecticut, and raised in nearby Fairfield.  He attended Berklee College of Music in Boston, but disenrolled and moved to Atlanta in 1997 with Clay Cook.  Together, they formed a short-lived two-man band called Lo-Fi Masters.  After their split, Mayer continued to play local clubs—refining his skills and gaining a following.  After his appearance at the 2001 South by Southwest Festival, he was signed to Aware Records, and then Columbia Records, which released his first EP, "Inside Wants Out".  His following two full-length albums—"Room for Squares" (2001) and "Heavier Things" (2003)—did well commercially, achieving multi-platinum status.  In 2003, he won the Grammy Award for Best Male Pop Vocal Performance for the single "Your Body Is a Wonderland".

Hinges (album): Hinges is the ninth and final volume in the Fuzzy Warbles series, released in September 2006.  The album is only available as a bonus CD in the 9-CD box set The Official Andy Partridge Fuzzy Warbles Collector's Album.  The Fuzzy Warbles Series brings together demos, rarities and side projects from XTC founding member Andy Partridge; the box set collects all 8 volumes, plus the "Hinges" bonus disc.

Explode Together: The Dub Experiments 78-80: Explode Together: The Dub Experiments 78-80 (1990) is an XTC compilation album which includes 'Mr Partridge's "Take Away/The Lure of Salvage" LP and the "Go +" EP.  Recorded during sessions on various breaks for the albums "Drums and Wires" and "Black Sea", the album consists of remixes with additional overdubs and sometimes new vocals recorded by Andy Partridge.  The material consists of tracks recorded for the band's first three albums.  Partridge would also occasionally write new lyrics for some of the compositions included here as well.

Clay Cook: Douglas "Clay" Cook (born April 20, 1978) is an American songwriter, producer and musician who co-wrote several songs with John Mayer including "No Such Thing", "Comfortable", "Man on the Side" and "Neon".  Cook and Mayer's songwriting partnership was predominantly through Mayer's early career, as the songs he wrote with Mayer (with the exception of live releases) only appear on Mayer's first two releases, "Inside Wants Out" and "Room for Squares".  Cook and Mayer formed the band Lo-Fi Masters prior to Mayer recording "Inside Wants Out".  Cook is currently a member of the Zac Brown Band and was formerly a member of the Marshall Tucker Band and Y-O-U.

Who Says (John Mayer song): "Who Says" is the thirteenth single released by American singer-songwriter John Mayer, and the first to be released from his fourth studio album, "Battle Studies".  It is Mayer's first studio recorded single release since "Say" in 2007.  On September 25, 2009, "Who Says" was released on John Mayer's official website.

John Mayer Trio: The John Mayer Trio is an American blues rock band that formed in 2005.  Comprising singer-songwriter and guitarist John Mayer, bassist Pino Palladino and drummer Steve Jordan, the band has released one live album, "Try! " in 2005.  Three of the songs on the album were co-written by Jordan, Mayer, and Palladino, and the album was co-produced by Mayer and Jordan.

John Mayer 2008 Summer Tour: The John Mayer 2008 Summer Tour is a concert tour by musician John Mayer to support his third album, "Continuum".  The tour has been heavily covered by tabloids due to Mayer's relationship with Jennifer Aniston.

Andy Partridge: Andrew John Partridge (born 11 November 1953) is an English singer, songwriter, guitarist, and record producer who co-founded the rock band XTC.  He lives in Swindon, Wiltshire, where he was raised.

The Village Sessions: The Village Sessions is an EP released by artist John Mayer on December 12, 2006.  Collaborators include John Mayer Trio members Steve Jordan and Pino Palladino, along with Ben Harper, Robbie McIntosh, and Ricky Peterson of Mayer's touring band and former producer for Prince albums.  The six-song EP contains acoustic and alternate versions of songs found on Mayer's third studio album, "Continuum", and his trio's live album, "Try! ".  Mayer co-produced the album with engineer Chad Franscoviak.

Supporting paragraphs: Andy Partridge John Mayer
Answer: guitarist