"Sgt. Pepper" informed Frank Zappa's parody of the counterculture and flower power on the Mothers of Invention's 1968 album "We're Only in It for the Money". By 1968, according to music critic Greil Marcus, "Sgt. Pepper" appeared shallow against the emotional backdrop of the political and social upheavals of American life. Simon Frith, in his overview of 1967 for "The History of Rock", said that "Sgt. Pepper" "defined the year" by conveying the optimism and sense of empowerment at the centre of the youth movement. He added that the Velvet Underground's "The Velvet Underground & Nico" – an album that contrasted sharply with the Beatles' message by "offerno escape" – became more relevant in a cultural climate typified by "the Sex Pistols, the new political aggression, the rioting in the streets" during the 1970s. while Colin Larkin states in his "Encyclopedia of Popular Music": "[it turned out to be no mere pop album but a cultural icon, embracing the constituent elements of the 60s' youth culture: pop art, garish fashion, drugs, instant mysticism and freedom from parental control."