According to the Angelfire website, Lennon and McCartney are an unusually polarized songwriting team. The personal relationships that the Beatles shared were constantly changing, John Lennon was clearly the acknowledged leader. To begin with, Lennon had more of a vision of what the Beatles were about and what they could be. Lennon had a rebellious nature that asked provoking questions, confronted assumptions and societal norms, and challenged authority.
One could infer that when Lennon looked at himself and the world around him, he felt dissatisfied and wanted to be an agent for change. McCartney's lyrics have been described as often being witty, charming, narrative, or sentimental. Lennon's can be acerbic, confessional, confrontational, critical and obtuse. As musicians, their personalities complement each other, enlarging the scope of what would otherwise be individual statements. Paul's lyrical harmony tended to tone down Lennon's intensity. If they did not always work together when writing even though the publishing citations still credit them jointly, they were collaborators and offered ideas to each other throughout their involvement with the Beatles (The Music and Magic of Lennon-McCartney).
According to Ger Tillekens in an essay titled: "Baroque and folk and...John Lennon" on the Soundscapes website, Tillekens writes that Nowadays this alleged musical discrepancy between McCartney and Lennon crops up in almost every historical and musical description and analysis of the group. Differences in musical style between Lennon and McCartney were, from the beginning, quite distinct. Reflecting his sedentary, ironic personality, Lennon's melodies tend to move up and down as little as possible, weaving deviously through their harmonies in chains of repeated notes. McCartney's lines, by contrast, display his extrovert energy and optimism, ranging freely across the stave in wide intervals and often encompassing more than an octa...