Holly was playing with Joe Maphis in 1963 when he was asked by Don Rich to fill in as bassist for the Buckaroos. The spot became his permanently after Merle Haggard left the group, and the Buckaroos began their most creative and successful period, from 1963 to 1971. The group had more than 30 singles in the country music top 40 in that time, of which more than half went to No. 1. "Act Naturally," a No. 1 single for the Buckaroos in 1963, was covered by The Beatles on their 1965 album "Help!" Other hits included "I've Got A Tiger By The Tail," "Together Again," and "Love's Gonna Live Here," which occupied the top position on the country chart for 17 weeks near the end of 1963.