examples, Frank Zappa and the Mothers of Invention's debut album Freak Out! (June 1966) came to be seen as "the first successful incorporation of art music in a pop context". With Los Angeles as his base since the early 1960s, Zappa was able to work in an environment where student radicalism was closely aligned with an active avant-garde scene, a setting that placed the city ahead of other countercultural centres at the time and would continue to inform his music. Writer and pianist Michael Campbell comments that the album "contains a long noncategorical list of Zappa's influences, from classical avant-garde composers to obscure folk musicians". The Beatles' Revolver (August 1966) furthered the album-as-art perspective and continued pop music's evolution. Led by the art-rock single "Eleanor Rigby", it expanded the genre's scope in terms of the range of musical styles, which included Indian, avant-garde and classical, and the lyrical content of the album, and also in its departure from previous notions of melody and structure in pop songwriting. According to Rolling Stone, "Revolver signaled that in popular music, anything – any theme, any musical idea – could now be realized." As with Rubber Soul, the album inspired many of the progressive rock artists of the 1970s, and each of its songs has been recognised as anticipating a new subgenre or style. 1967 Clash Music names the Velvet Underground's debut March 1967 album The Velvet Underground & Nico "the original art-rock record". Bannister writes of the Velvet Underground: "no other band exerted the same grip on the minds of 1970s/1980s art/alternative rock artists, writers and audiences." Their influence would recur from the 1970s onwards to various worldwide indie scenes, and in 2006, The Velvet Underground & Nico was inducted into the Library of Congress' National Recording Registry, who commented: "For decades [it] has cast a huge shadow over nearly every sub-variety of avant-garde rock, from 70s art-rock to no-wave, new-wave, and punk." However, when the Velvet Underground first appeared in the mid 1960s, they faced rejection and were commonly dismissed as a "fag" band. In 1982, musician Brian Eno famously stated that while The Velvet Underground & Nico initially sold just 30,000 copies, "everyone who bought one of those 30,000 copies started a band." The Beatles' Paul McCartney deemed Pet Sounds "the record of the time", and in June 1967, the band responded with their own album: Sgt. Pepper's, which was also