sentences:  In 1960, they signed with the major label Warner Bros. Records and recorded "Cathy's Clown", written by the brothers themselves, which was their biggest selling single.The brothers enlisted in the United States Marine Corps Reserve in 1961, and their output dropped off, though additional hit singles continued through 1962, with "That's Old Fashioned (That's the Way Love Should Be)" being their last top-10 hit.Long-simmering disputes with Wesley Rose, the CEO of Acuff-Rose Music, which managed the group, a growing drug usage in the 1960s, as well as changing tastes in popular music, led to the group's decline in popularity in its native U.S., though the brothers continued to release hit singles in the U.K. and Canada, and had many highly successful tours throughout the 1960s.