The Clefs released three singles in 1966: "I Can Only Give You Everything"/"Roberta," "Last Night"/"March of the Siamese Twins," and "A Boy Like Me"/"Bring It to Jerome." Harris left to join the Groove in 1967 and McAskill became the leader. After a suggestion from their manager, the Clefs changed their name to the Levi Smith's Clefs that year. The band then moved to Sydney where they took up a residency at the Whisky a Go Go club. The lineup changed several times and by 1968 was composed of McAskill, Inez Amaya (vocals), Michael Carlos (organ), John Blake (drums), Mick Jurd (guitar), Richard Lockwood (flute, sax), and Robert Taylor (drums).

By the end of 1968, Carlos, Lockwood, Blake, and Taylor left to form the band Tully, which backed the Australian production of Hair later that year, followed by Amaya, who left to join the cast. A new lineup of McAskill, Mick Jurd, John Bissett (organ), Bruce Howe (bass), and Tony Buettel (drums) recorded and released the Empty Monkey album in 1970. Two singles were released from the album, "Lisa"/"Roadrunner" (January 1970) and a cover of Junior Walker's "Shotgun"/"Who Is It That Shall Come?" (April 1970).

Several lineup changes followed and a new band known as Barrie McAskill's Levi Smith's Clefs released the singles "Live Like a Man"/"Piece of My Heart" (September 1970) and "Gonna Get a Seizure"/"Dancing and Drinking" (April 1971), as well as a shared EP with the band Autumn, Best of Whisky A Go Go. The band played Sydney's infamous Chequers club throughout 1971.

Several lineup changes followed again, and by late 1971, the lineup of McAskill, Carlos, Stirling, Henson, and Jeffrey toured as Barrie McAskill's Bear Brigade and McAskill's Marauders. By mid-1972, McAskill was touring with another Levi Smith's Clefs lineup, but the band was coming to an end, and by 1976, McAskill was touring under his own name. In the coming years he played in and formed several bands in Adelaide, the Levi Smith's Clefs among them.