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Use of studio musicians

Biographer James Murphy said, "By most contemporary accounts, they were not a very good live band when they started.... The Beach Boys learned to play as a band in front of live audiences", eventually to become "one of the best and enduring live bands". With only a few exceptions, the Beach Boys played every instrument heard on their first four albums and first five singles. It is the belief of Richie Unterberger that, "Before session musicians took over most of the parts, the Beach Boys could play respectably gutsy surf rock as a self-contained unit."

As Wilson's arrangements increased in complexity, he began employing a group of professional studio musicians, later known as " the Wrecking Crew ", to assist with recording the instrumentation on select tracks. According to some reports, these musicians then completely replaced the Beach Boys on the backing tracks to their records. Much of the relevant documentation, while accounting for the attendance of unionized session players, had failed to record the presence of the Beach Boys themselves. These documents, along with the full unedited studio session tapes, were not available for public scrutiny until the 1990s.

Wilson started occasionally employing members of the Wrecking Crew for certain Beach Boys tracks during the 1963 Surfer Girl sessions – specifically, on two songs, "Hawaii" and "Our Car Club". The 1964 albums Shut Down Volume 2 and All Summer Long featured the Beach Boys themselves playing the vast majority of the instruments while occasionally being augmented by outside musicians. It is commonly misreported that Dennis in particular was replaced by Hal Blaine on drums. Dennis's drumming is documented on a number of the group's singles, including 1964's "I Get Around", "Fun, Fun, Fun", and "Don't Worry Baby". Starting with the 1965 albums Today! and Summer Days, Brian used the Wrecking Crew with greater frequency, "but still", Stebbins writes, "the Beach Boys continued to play the instruments on many of the key tracks and single releases."

Overall, the Beach Boys played the instruments on the majority of their recordings from the decade, with 1966 and 1967 being the only years when Wilson used the Wrecking Crew almost exclusively. Pet Sounds and Smile are their only albums in which the backing tracks were largely played by studio musicians. After 1967, the band's use of studio musicians was considerably reduced. Wrecking Crew biographer Kent Hartman supported in his 2012 book about the musicians, "Though had for several months brought in various session players on a sporadic, potluck basis to supplement things, the other Beach Boys generally played on the earliest songs, too."

The source of the longstanding controversy regarding the Beach Boys' use of studio musicians largely derives from a misinterpreted statement in David Leaf's 1978 biography The Beach Boys and the California Myth, later bolstered by erroneous recollections from participants of the recording sessions. Starting in the 1990s, unedited studio session tapes, along with American Federation of Musicians (AFM) sheets and tape logs, were leaked to the public. Music historian Craig Slowinski, who contributes musician credits to the liner notes of the band's reissues and compilations, wrote in 2006: "nce the vaults were opened up and the tapes were studied, the true situation became clear: the Boys themselves played most of the instruments on their records until the Beach Boys Today! album in early 1965." Slowinski goes on to note, "when painting a picture of a Beach Boys recording session, it's important to examine both the AFM contracts and the session tapes, either of which may be incomplete on their own."

During the period when Brian relied heavily on studio musicians, Carl was an exception among the Beach Boys in that he played alongside the studio musicians whenever he was available to attend sessions. In Slowinski's view, "One should not sell short Carl's own contributions; the youngest Wilson had developed as a musician sufficiently to play alongside the horde of high-dollar session pros that big brother was now bringing into the studio. Carl's guitar playing a key ingredient."