Author Matthew Bannister traces "the more self-conscious, camp aesthetic of art rock" to pop artist Andy Warhol and the Velvet Underground, who emulated Warhol's art/pop synthesis. Accordingly: "Warhol took Spector's combination of the disembodiment, 'distance' and refinement of high culture with the 'immediacy' of mass cultural forms like rock and roll several stages further ... But Warhol’s aesthetic was more thoroughly worked out than Spector's, which represented a transitional phase between old-fashioned auteurism and the thoroughly postmodern, detached tenets of pop art. ... Warhol's approach reverberates throughout art rock, most obviously in his stance of distance and disengagement." In 1969, the Doors also explored art rock genre on their fourth album, "The Soft Parade".