Pop star Lady Gaga and crooner Tony Bennett brought a mix of Cole Porter, Duke Ellington, Frank Sinatra and even Edith Piaf to a sell-out crowd spanning generations at the Montreux Jazz Festival on Monday night. Legendary producer Quincy Jones introduced the odd American couple, praising Gaga as a singer who had “blown his mind.” He also recalled working on the musical arrangement for Bennett’s 1966 hit “Girl Talk.