Room for Squares is the debut studio album of American musician John Mayer, released September 18, 2001 on Columbia Records in the United States. Originally released independently through Aware Records on June 5, 2001, the album peaked at number 9 on the U.S. Billboard 200 chart. Upon its release, Room for Squares received generally positive reviews from most music critics and earned Mayer a Grammy Award for Best Male Pop Vocal Performance for the single "Your Body Is a Wonderland". It remains as his best-selling album to date, with sales of over 4,308,000 copies in the U.S. as of July 2009.

The album's title is a reference to Hank Mobley's No Room for Squares album. All songs from the album are written by Mayer; three songs, "No Such Thing", "Neon", and "Love Song for No One", were co-written with Clay Cook. The first and third of these, along with "My Stupid Mouth" and "Back to You," originally appeared on Mayer's 1999 EP Inside Wants Out.

Henry (Hank) Mobley (July 7, 1930 – May 30, 1986) was an American hard bop and soul jazz tenor saxophonist and composer. Mobley was described by Leonard Feather as the "middleweight champion of the tenor saxophone", a metaphor used to describe his tone that was neither as aggressive as John Coltrane nor as mellow as Stan Getz. In addition, as his style was laid-back, subtle and melodic, especially in contrast with players like Sonny Rollins and Coltrane. The critic Stacia Proefrock claimed he is "one of the more underrated musicians of the bop era."

Mobley was born in Eastman, Georgia, but was raised in Elizabeth, New Jersey, near Newark. When he was 16, an illness kept him in the house for several months. His uncle thought of buying a saxophone to help him occupy his time. It was then that Mobley began to play sax. He tried to enter a music school in Newark, but couldn't, since he was not a resident, so he kept studying through books at home. At 19, he started to play with local bands and, months later, worked for the first time with musicians like Dizzy Gillespie and Max Roach. He took part in one of the earliest hard bop sessions, alongside Art Blakey, Horace Silver, Doug Watkins and trumpeter Kenny Dorham. The results of these sessions were released as Horace Silver and the Jazz Messengers. They contrasted with the classical pretensions of cool jazz, with Mobley's rich lyricism being bluesier, alongside the funky approach of Horace Silver. When The Jazz Messengers split in 1956, Mobley continued on with pianist Horace Silver for a short time, although he did work again with Blakey some years later, when the drummer appeared on Mobley's albums in the early 1960s.

Joseph Rudolph (Philly Joe) Jones (July 15, 1923 – August 30, 1985) was a Philadelphia-born American jazz drummer, known as the drummer for the Miles Davis Quintet.

Philly Joe Jones was often confused with another influential jazz drummer, Jo Jones. The two died only a few days apart from each other.

In 1947 he became the house drummer at Café Society in New York City, where he played with the leading bebop players of the day. Among them, the most important influence on Jones was Tadd Dameron. Jones toured and recorded with Miles Davis Quintet from 1955 to 1958 – a band that became known as "The Quintet" (along with Red Garland on piano, John Coltrane on sax, and Paul Chambers on bass). Miles acknowledged that Jones was his favorite drummer (in his autobiography, Davis mentions that he would always listen for Jones in other drummers).

From 1958 onwards Jones worked as a leader, but continued to work as a sideman with other musicians, including Bill Evans and Hank Mobley. Evans also openly admitted that Philly Joe was his all-time favorite drummer. For two years (1967–69) he taught at a specially organized school in Hampstead, London, but was prevented from otherwise working in the UK by the Musicians' Union.

John Clayton Mayer ( /ˈmeɪ.ər/ MAY-ər; (born October 16, 1977) is an American pop and blues rock musician, singer-songwriter, recording artist, and music producer. Born in Bridgeport, Connecticut and raised in Fairfield, Connecticut, he attended Berklee College of Music in Boston. He moved to Atlanta in 1997, where he refined his skills and gained a following, and he now lives in New York City. His first two studio albums, Room for Squares and Heavier Things, did well commercially, achieving multi-platinum status. In 2003, he won a Grammy Award for Best Male Pop Vocal Performance for "Your Body Is a Wonderland."

Mayer began his career performing mainly acoustic rock, but gradually began a transition towards the blues genre in 2005 by collaborating with renowned blues artists such as B. B. King, Buddy Guy, and Eric Clapton, and by forming the John Mayer Trio. The blues influence can be heard throughout his 2005 live album Try! with the John Mayer Trio and his third studio album Continuum, released in September 2006. At the 49th Annual Grammy Awards in 2007 Mayer won Best Pop Vocal Album for Continuum and Best Male Pop Vocal Performance for "Waiting on the World to Change". He released his fourth studio album, Battle Studies, in November 2009. His fifth album, Born and Raised, was released on May 22, 2012. He has sold over 10 million albums in the U.S. and 20 million albums worldwide.

Douglas "Clay" Cook (born April 20, 1978) is a songwriter, producer and musician who co-wrote several songs with Grammy-winner John Mayer including "No Such Thing", "Comfortable", 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 in the Zac Brown Band and was formerly in the Marshall Tucker Band and Y-O-U.

Clay Cook attended Smoke Rise Elementary, Tucker High School, and is a graduate of South Gwinnett High School in Snellville, Georgia in 1996. Following this, Cook enrolled at Berklee College of Music in Boston, Massachusetts to further his skills in music. While there, Cook met fellow student and singer-songwriter John Mayer. The two of them formed the duo known as Lo-Fi Masters, putting 5 of their songs on an eponymous demo tape which was made at Berklee.