After Kooper left the group, Colomby and Katz began to look for a new vocalist, considering Alex Chilton (after the breakup of soul-rock group the Box Tops but before the formation of Big Star), Stephen Stills, and Laura Nyro. Ultimately, they decided upon David Clayton-Thomas, a Canadian singer, born in Surrey, England. Reportedly, folk singer Judy Collins had seen Clayton-Thomas perform at a New York City club and was so taken and moved by his performance that she told Colomby and Katz about him (knowing that they were looking for a new lead singer to front the band). With her prodding, they went to see Clayton-Thomas perform and were so impressed that he was offered the role of lead singer in a re-constituted Blood Sweat & Tears. Trombonist Halligan took up the organ chores and Jerry Hyman joined to take over trombone. With new trumpeters Soloff and Winfield the now nine-member band debuted at New York's Cafe Au Go Go on June 18, 1968, beginning a two-week residency.