melodrama". The band's stylistic range expanded in another direction with their 1966 B-side "Rain", described by Martin Strong as "the first overtly psychedelic Beatles record". Other psychedelic numbers followed, such as "Tomorrow Never Knows" (recorded before "Rain"), "Strawberry Fields Forever", "Lucy in the Sky with Diamonds" and "I Am the Walrus". The influence of Indian classical music was evident in Harrison's "The Inner Light", "Love You To" and "Within You Without You" – Gould describes the latter two as attempts "to replicate the raga form in miniature". Innovation was the most striking feature of their creative evolution, according to music historian and pianist Michael Campbell: "'A Day in the Life' encapsulates the art and achievement of the Beatles as well as any single track can. It highlights key features of their music: the sound imagination, the persistence of tuneful melody, and the close coordination between words and music. It represents a new category of song – more sophisticated than pop ... and uniquely innovative. There literally had never before been a song – classical or vernacular – that had blended so many disparate elements so imaginatively." Philosophy professor Bruce Ellis Benson agrees: "the Beatles ... give us a wonderful example of how such far-ranging influences as Celtic music, rhythm and blues, and country and western could be put together in a new way." Author Dominic Pedler describes the way they crossed musical styles: "Far from moving sequentially from one genre to another (as is sometimes conveniently suggested) the group maintained in parallel their mastery of the traditional, catchy chart hit while simultaneously forging rock and dabbling with a wide range of peripheral influences from country to vaudeville. One of these threads was their take on folk music, which would form such essential groundwork for their later collisions with Indian music and philosophy." As the personal relationships between the band members grew increasingly strained, their individual tastes became more apparent. The minimalistic cover artwork for the White Album contrasted with the complexity and diversity of its music, which encompassed Lennon's "Revolution 9" (whose musique concrète approach was influenced by Yoko Ono), Starr's country song "Don't Pass Me By", Harrison's rock ballad "While My Guitar Gently Weeps", and the "proto-metal roar" of McCartney's "Helter Skelter". Contribution of George Martin George Martin's close involvement in his role as producer made him one of the leading candidates for the informal title of the "fifth