The Beatles (album) stereo only. In the UK, the following album, "Yellow Submarine", was the last to be shipped in mono. The mono version of "The Beatles" was made available worldwide on 9 September 2009, as part of "The Beatles in Mono" CD boxed set. A reissue of the original mono LP was released worldwide in September 2014. The album's sleeve was designed by pop artist Richard Hamilton, in collaboration with McCartney. Hamilton's design was in stark contrast to Peter Blake's vivid cover art for "Sgt. Pepper's Lonely Hearts Club Band", and consisted of a plain white sleeve. The band's name, in Helvetica,
Progressive pop of author Simon Philo, the Beatles' progressive pop was exemplified in the double A-sided single "Strawberry Fields Forever" / "Penny Lane" (1967). In a further example of the reciprocal influences between themselves and the Beach Boys, the Beatles demonstrated "paradoxical lyrical content matched by music that was at once 'young' and 'old', rock and Tin Pan Alley, LSD and cocoa, progressive and nostalgic" – all features that were shared on "Sgt. Pepper's". Musicologist Allan Moore writes: "At that time, "Sgt. Pepper" seemed to mark rock music's coming of age ... Now, of course, with jaded memories, we think of it