 Pepper" as the birth of progressive rock, Everett and Bill Martin recognise "Rubber Soul" as the inspiration for many of the bands working in that genre from the early 1970s.As with "Revolver", Everett sees the album's progressive rock antecedents among its combination of "rich multipart vocals brimming with expressive dissonance treatment, a deep exploration of different guitars and the capos that produced different colors from familiar finger patterns, surprising new timbres and electronic effects, a more soulful pentatonic approach to vocal and instrumental melody tinged by frequent twelve-bar jams that accompanied the more serious recording, and a fairly consistent search for meaningful ideas in lyrics".