Elvis Costello, London Nashville Rooms — Thursday, Friday and Saturday, December 22, 23 and 24. Sold out. Support bands: The Pop Group (Thursday), Boyfriends (Friday and Saturday). Doors open 7 p.m. Costello is another artist to have meteored to mass recognition in a very short time. He fits into the Dylan/ Springsteen / Parker / Morrison mould perfectly, and some say that his whimsical lyricism and melodies will elevate him to legendary status. Another artist desperate to keep in touch with his roots by playing the small clubs, but with a growing audience.