Since the 1960s, it has been the standard bearer in London for stylish, American-style jazz, and it honors a long tradition of pairing visiting U.S. greats with local acts. But the old dive got ritzy. After a £2.1-million renovation, the 255-seater began charging prices in the £45 range. But it’s true that the club draws names, including Patti Austin, Van Morrison, Tom Waits, Cleo Laine, Chaka Khan, and Frank Sinatra, Jr.