Sebastian was joined by Zal Yanovsky, Steve Boone, and Joe Butler in the Spoonful, which was named after "The Coffee Blues," a Mississippi John Hurt song. The Lovin' Spoonful, which blended folk-rock and pop with elements of blues, country, and jug band music, became part of the American response to the British Invasion, and was noted for such hits as "Do You Believe in Magic", "Jug Band Music", "You Didn't Have to Be So Nice", "Daydream", "Did You Ever Have to Make Up Your Mind?", "Summer in the City", "Rain on the Roof", "Nashville Cats", "Darling Be Home Soon", and "Six O'Clock".
The band, however, began to implode after a 1966 marijuana bust in San Francisco involving Boone and Yanovsky, a Canadian citizen. Facing deportation, they revealed the name of their dealer to police, which caused a fan backlash and added to the internal tension already created by the diverging interests of the band members. Neither Sebastian nor Butler were involved in the matter, both being away from San Francisco at the time. Yanovsky subsequently left the band and was replaced by Jerry Yester, after which the band's musical style veered away from its previous eclectic blend and became more pop-oriented.
