He taught himself classical guitar, at age 24, inspired by the playing of Don Costa, who had started on that instrument before becoming one of the most important arrangers in popular music. He played rhythm guitar on some tracks on Bob Dylan's album Bringing it All Back Home (1965). Rankin developed a considerable following during the 70s with a steady flow of albums, three of which broke into the Top 100 of the Billboard Album Chart. His liking for jazz was evident from an early age, but the times were such that in order to survive his career had to take a more pop-oriented course, and he cited singer-songwriter Laura Nyro consistently as a major influence. 