Experimental rock
In the late 1960s, groups such as the Mothers of Invention, the Velvet Underground, the Fugs, the Beatles, and the Jimi Hendrix Experience began incorporating elements such as avant-garde music, sound collage, and poetry in their work.  Author Doyle Greene identifies the Beatles, Frank Zappa, the Velvet Underground, Plastic Ono Band, Captain Beefheart, and Nico as "pioneers of avant-rock", though also noted "proto-prog" bands such as Pink Floyd and the Soft Machine as an influence. In addition, The Quietus Ben Graham described duos the Silver Apples and Suicide as antecedents of avant-rock.