From the end of The Beatles to the beginning of Led Zeppelin, these are some of the major events that happened on this day in rock history. Cowritten by John Lennon and Carlos Alomar, it was Bowie's first U.S. No. Cultural MilestonesSept. 20 also witnessed two pivotal rock culture moments:1968: Led Zeppelin began working on their self-titled debut album at London's Olympic Studios, while they were still calling themselves the New Yardbirds. Led Zeppelin began working on their self-titled debut album at London's Olympic Studios, while they were still calling themselves the New Yardbirds. 1969: John Lennon informed the other band members that he was leaving The Beatles.