DOM AND CHER.

The other night, the comedian Dom Irrera sat on a ratty sofa backstage at Madison Square Garden, waiting to go on as Cher's opening act. The platters of crudites and bite-size Mr. Goodbars on his dressing-room table looked as if they'd gone undisturbed since about 1974. Irrera's girlfriend, Sophie Perreault, who was wearing a barely sufficient leopard-print bustier, poured herself a glass of red wine and sat down beside him.

"What about me?" Irrera said. "I gotta go on in front of twenty thousand people."

"You're not as good when you drink," Perreault replied.

"I'm good when I drink," he said. "I'm not good when I'm drunk." Irrera is in his late forties and has a doughy, resigned face. He made his name with wise-guy routines punctuated by catchphrases-- "Bada-boom, bada-bing!"; "Fuhgeddaboutit!"--from his Italian-American neighborhood in South Philadelphia, and his choice of white athletic socks under black jeans indicated that he was still keeping it real.

Irrera first opened for Cher in 1990, when he was less established, and he seemed bewildered to be on board thirteen years later for her farewell tour, which has already logged more than a hundred and forty shows and is scheduled to last, Irrera said, "another twenty, twenty-five years." He added, "There's no connection at all between our acts. I guess she just likes having me on the bus--we actually sleep in the same roll-out cot." Bada-boom, bada-bing!

There is a noble tradition of comedians kicking things off for singers who just like having them around: Tom Dreesen often opened for Sinatra, as Sammy Shore did for Elvis. There is an equally noble tradition of comedians complaining about the gig. "The rooms are too big, and no one is there to see you," said Irrera, who once opened for Joan Jett at the Asbury Park Convention Hall and was booed off the stage after three minutes. "Brad Garrett, from ...