The group's second-biggest hit record (after 'A Whiter Shade of Pale'), in turn, helped lift the album into the American Top Five. Wilson's powerful drumming - helped loft the single to number 16 in America. They did it cold, opening the concert, and the eventual album featured a performance - highlighted by the orchestra's brass in a Spanish mode, running scales on the strings, and B.J. Even 'Conquistador,' the song on which the resulting album's commercial success was built, was added at the last minute, with no time for the orchestra to rehearse the arrangement that Brooker wrote on the flight from England. Amid all of the preparation - including the writing of new orchestral arrangements by Gary Brooker and with a new lead guitarist, Dave Ball, just joining the lineup - Brooker decided that it might be a good idea to preserve a professionally made tape of the show and suggested that A&M Records, to which they were signed, might want to record the performance the label agreed with just a week to go until the concert. This whole album was an afterthought - Procol Harum had been invited to play a concert with the Edmonton Symphony Orchestra and the Da Camera Singers in Edmonton, Alberta, Canada, in August of 1971, at the tail-end of their last tour with Robin Trower in the lineup.
