Joan Cushing thinks Washington is funny.

She thinks Liz Taylor, politicians, socialites, the Rev. Sun Myung Moon, Hechinger's, Ling-Ling, Frank Perdue, secretaries and singles are all funny. And if you hear her some Friday or Saturday night at Cafe Lafayette in Old Town, you'll probably agree.

Not as politically witty as Mark Russell or as brash as Joan Rivers, Cushing is a low- key, tongue-in-cheek satirist who's at her best at the piano, singing cleverly revised lyrics to familiar songs. In her version of "Fiddler on the Roof," she suggests that Liz Taylor and the pandas call on proven matchmaker Moon for help. One line begs the reverend to "find me a find, nail me a male, in between hearings and going to jail."

Singles looking for mates are not overlooked: In a tune about the Hechinger Sunday newspaper supplement, Cushing sings, "I'm in heaven in Hechinger's, when I walk down the aisle, there's lots of studs among the 2 x 4s . . . No matter at which branch you are, it's really just a singles bar, at Hechinger's hardware store . . ."

Frank Perdue's chicken advertising has also caught her eye, and she wants to keep a leg up on the "tough man." In "The Golden Moment," she imagines rows of chickens lined up outside a theater waiting to audition for a Perdue production of "A Chorus Line."

And even real magazine "personals" find their way into song. "Former feminist, 38, now allowing men to buy her drinks," sings Cushing. Later, during a break between sets, she says she "used to add a punch line" to make the personals funny, but a changed climate in classified honesty has been good for the funnybone: "I haven't changed one for months!" JOAN CUSHING -- Friday and Saturday nights with sets at 9:30, 10:30, 11:30 and 12:30 at Cafe Lafayette in the Fire Escape Lounge, 105 North Alfred Street, Alexandria. 548-0076. Minimum $6.