Final answer:
Lennon missed some of the early sessions of Abbey Road because he was involved in the Woodstock music festival and took psychedelic drugs.
Step-by-step explanation:
In 1969, Lennon missed some of the early sessions of Abbey Road, the Beatles' eleventh studio album, because of his involvement in the Woodstock music festival.
Woodstock was a significant event that took place in upstate New York and attracted half a million people, including Lennon.
He was present at the festival and took LSD, a psychedelic drug, which caused him to miss some recording sessions.