The two follow-up singles were almost as successful, but it began a brief dry run before their biggest hit and signature song, "Happy Together" (1967, 1967 in music), which spent three weeks atop the American charts. The follow-up, "She'd Rather Be With Me" was bigger than "Happy Together" outside of the US, and a few more successful singles followed as personnel shifts wracked the group.
During the late 1960s, The Turtles tried to stay with the times and add more psychedelic influences, but the first few singles failed to sell well. In 1968 (see 1968 in music), The Turtles released a concept album called The Turtles Present the Battle of the Bands, in which the group pretended to be eleven different bands, each with a song. "Elenore" and "You Showed Me" were Top Ten singles. Kaylan and Volman then rebelled against White Whale's attempts to push The Turtles towards Monkees-style studio chicanery, and they recorded Turtle Soup, a critically well-received album that was inspired by The Kinks' Village Green Preservation Society. In spite of Turtle Soup's critical success, commercial acclaim was low and the band soon began disintegrating.
Kaylan and Volman joined the Mothers of Invention as Phlorescent Leech & Eddie, since the use of The Turtles was prohibited by their contract with White Whale. Flo & Eddie, as they soon became known, also recorded for children's movies like The Care Bears and Strawberry Shortcake and began hosting their own radio show on KROQ in Los Angeles and WXRK in New York City. In 1984 (see 1984 in music), Kaylan and Volman regained the use of The Turtles and began touring as The Turtles...Featuring Flo and Eddie.