Don't tell that to Billy Shears!
But seriously, from WIKI:
The album was loosely
conceptualised as a performance by the fictional Sgt. Pepper band, an idea that was conceived after recording
the title track. A key work of British
psychedelia, it incorporates a range of stylistic influences, including
vaudeville,
circus,
music hall,
avant-garde, and
Western and
Indian classical music.
Sgt. Pepper is regarded by musicologists as an early
concept album that advanced the roles of sound composition,
extended form, psychedelic imagery,
record sleeves, and the producer in popular music. The album had an immediate cross-generational impact and was associated with numerous touchstones of the era's youth culture, such as fashion, drugs,
mysticism, and a sense of optimism and empowerment. It is considered one of the first
art rock LPs, a progenitor to
progressive rock, and the start of the
album era. In 1968, it won four
Grammy Awards, including
Album of the Year, the first rock
LP to receive this honour;
In November, during his and Evans' return flight from Kenya, McCartney had an idea for a song that eventually formed the impetus of the
Sgt. Pepper concept.[14] His idea involved an
Edwardian-era military band, for which Evans invented a name in the style of contemporary San Francisco-based groups such as
Big Brother and the Holding Company and
Quicksilver Messenger Service.
[29][nb 2] In February 1967, McCartney suggested that the new album should represent a performance by the fictional band.
[31] This alter ego group would give them the freedom to experiment musically by releasing them from their image as Beatles.
[32] Martin recalled that the
concept was not discussed at the start of the sessions,
[33] but it subsequently gave the album "a life of its own"