Roma bands like Taraf de HaÏdouks, left, have fans across Europe dancing in the aisles
Union chapel, a stately congregational church in the upscale London borough of Islington, is often rented out for summer events. So the crowd of concertgoers who gathered there on a breezy evening last month was nothing unusual. Except, that is, for the guy with the accordion. A portly man with long, thinning hair pulled into a ponytail, undaunted by the smart set in their $100 jeans and retro shirts, he stood in the main entranceway trying to hawk his damaged instrument. Politely ignored at first, he finally hooked a young woman and carefully played a tune that somehow avoided the twisted...
