got away from George Martin, and became a creative entity unto themselves". In 1995, Harrison said that Rubber Soul was his favourite Beatles album, adding: "we certainly knew we were making a good album. We did spend more time on it and tried new things. But the most important thing about it was that we were suddenly hearing sounds that we weren't able to hear before." During the sessions, McCartney played a solid-body Rickenbacker 4001 bass guitar, which produced a fuller sound than his hollow-body Hofner. The Rickenbacker's design allowed for greater melodic precision, a characteristic that led McCartney to contribute more intricate bass lines. Harrison used a Fender Stratocaster for the first time, most notably in his lead guitar part on "Nowhere Man". The variety in guitar tones throughout the album was also aided by Harrison and Lennon's use of capos, such as in the high-register parts on "If I Needed Someone" and "Girl". On Rubber Soul, the Beatles departed from standard rock and roll instrumentation, particularly in Harrison's use of the Indian sitar on "Norwegian Wood". Having been introduced to the string instrument on the set of the 1965 film Help!, Harrison's interest was fuelled by fellow Indian music fans Roger McGuinn and David Crosby of the Byrds, partway through the Beatles' US tour. Music journalist Paul Du Noyer describes the sitar part as "simply a sign of the whole band's hunger for new musical colours", but also "the pivotal moment of Rubber Soul". The Beatles also made use of harmonium during the sessions, marking that instrument's introduction into rock music. The band's willingness to experiment with sound was further demonstrated in McCartney playing fuzz bass on "Think for Yourself" over his standard bass part, and their employing a piano made to sound like a baroque harpsichord on "In My Life". The latter effect came about when, in response to Lennon suggesting he play something "like Bach", Martin recorded the piano solo with the tape running at half-speed; when played back at normal speed, the sped-up sound gave the illusion of a harpsichord. In this way, the Beatles used the recording studio as a musical instrument, an approach that they and Martin developed further with Revolver. In Prendergast's description, "bright ethnic percussion" was among the other "great sounds" that filled the album. Lennon, McCartney and Harrison's three-part harmony singing was another musical detail that came to typify the