how he went about writing a song. In response, McCartney took Taylor into the dining room, where they both sat at a harmonium; McCartney then began playing the instrument and asked Taylor to call out the opposite to each word he happened to sing. Author Steve Turner writes of the result: "And so it went – black and white, yes and no, stop and go, hello and goodbye." Taylor later reflected: "I've no memory at all of the tune ... I wonder whether Paul really made up [the melody to] that song as he went along or whether it was running through his head already." Talking in the 1990s to his official biographer, Barry Miles, McCartney said that the lyrics address duality, reflecting his astrological sign of Gemini. He added: "It's such a deep theme in the universe, duality – man woman, black white, ebony ivory, high low, right wrong, up down, hello goodbye – that it was a very easy song to write." McCartney also said that, in "Hello, Goodbye", he was promoting "the more positive side of the duality". Among Beatles biographers, Ian MacDonald dates the composition to late September 1967, while Bob Spitz says it was written in time for the Our World international television broadcast, in June that year. According to Spitz, McCartney suggested "Hello, Goodbye" as the Beatles' contribution to Our World, an honour that instead went to the John Lennon-composed "All You Need Is Love". Composition "Hello, Goodbye" is in the key of C major and in 4/4 time. MacDonald describes the musical structure as "characteristically scalar" and founded on "a descending sequence in C", with "a brief touchdown on A flat as its only surprise". Musicologist Walter Everett writes that the bassline in the chorus is an inverted form of the descending scale, which is accentuated on the Beatles' recording by the lead guitar part. In Everett's estimation, much of "Hello, Goodbye" references previous Lennon–McCartney compositions: over the verses, the parallel thirds in the vocal recall the band's unreleased song "Love of the Loved", among others; melodically, the chorus is similar to the keyboard part on "For No One"; and the complementary vocal parts in the final verse recall "Help!" Everett also suggests that, early in "Hello, Goodbye", McCartney appears to be imitating the V–VI chord "ambivalence" of "Strawberry Fields Forever". Everett describes the composition as "derivative McCartney", for the most part, "freshened