Complex sentence: Garfunkel's poetic career began in 1981, while on the Simon & Garfunkel 1981--1982 tour in Switzerland, he was riding a motorcycle and began writing a poem describing the countryside.
Split into simpler sentences: Garfunkel's poetic career began in 1981, while on the Simon & Garfunkel 1981--1982 tour in Switzerland. He was riding a motorcycle and began writing a poem describing the countryside.