"Big Boy" (also known as "I'm a Big Boy Now") is the debut single by the The Jackson 5 and the first song sung by Michael Jackson. "Big Boy was released by Steeltown Records, a record company in Gary, Indiana, in January 1968. After it was released, the song played on radio stations in the Chicago-Gary area and was a local hit. Beginning in March 1968, Steeltown Records sold thousands of copies of "Big Boy" nationally through a distribution deal with Atlantic Records, but it was neither a critical nor commercial success. The Jackson family, however, were delighted with the outcome nonetheless. The Jackson 5 would release a second single on the "Steeltown" label before signing with Motown Records in Detroit, in 1969. The group played instruments on many of their Steeltown compositions, including "Big Boy". The group's recordings at Steeltown Records were thought to be lost, but they were rediscovered more than 25 years later. They were remastered and released in 1995, with "Big Boy" as the promotional lead single.

The Jackson 5 began their career performing at talent contests, which they would often win. During a performance at Beckman Junior High in Gary, Indiana, the group were brought to the attention of Gordon Keith — a singer, record producer, and a founder-owner of Steeltown Records, a small record company located in Gary. Keith, Steeltown Records president in 1967, signed "The Jackson Five" to six-month contract with him (each Steeltown Records co-owner individually discovered, signed, managed, and received any profit for each signed individual or group, using Steeltown Records (Steeltown label) as an umbrella to promote name recognition) in November of that year, producing and releasing "Big Boy" on January 30, 1968.

The band recorded with their instruments and a backing group on the weekends. Michael Jackson sang lead vocals on the majority of the tracks beginning with "Big Boy" in 1967, which took a few hours to record at Sunny Sawyers recording studio in South Chicago. "Big Boy" was written by Eddie Silvers, a Chicago musician. According to legend, the group were paid three cents for each record sold, which was equally split among the five brothers and their drummer. The group's first single "Big Boy", was backed with the B-side "You've Changed". "The Jackson Five Plus Johnny" (Johnny Jackson on drums, no relation) would go on to perform "Big Boy" and other songs locally throughout the Gary and South Chicago area before moving to California in 1969.

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