Best remembered for their bizarre chart smash "Hocus Pocus," Dutch progressive rock band Focus was formed in Amsterdam in 1969 by vocalist/keyboardist/flutist Thijs van Leer, bassist Martin Dresden, and drummer Hans Cleuver. With the subsequent addition of guitarist Jan Akkerman, the group issued its debut LP, In and Out of Focus, in 1970, earning a European cult following thanks to the single "House of the King." Dresden and Cleuver were replaced by bassist Cyril Havermanns and drummer Pierre Van der Linden for the English-language follow-up, Moving Waves; the record generated the hit "Hocus Pocus," a hallucinatory epic distinguished by Akkerman's guitar pyrotechnics and van Leer's demented yodeling.