The barbershop quartet is a fine piece of musical Americana. The snappy outfits, boisterous, enthusiastic singers and the good, clean harmonies make for good, clean fun. There's nothing to tempt the mind or fire the imagination, but everyone enjoys themselves.

The Starland Vocal Band is Washington's pop version of a barbershop quartet. The group, which appeared last night at the Cellar Door (where it will be featured through Wednesday night), mixed immaculate vocals, sprightly stage patter and nifty covers of pop classics in a show that was a rollicking, if somewhat innocuous, nighttime delight.

From the opening a cappella version of "Why Do Fools Fall in Love?" to a foot-stomping rendition of "La Bamba," the singers proved to be both precise and energetic.Margot Kunkel's soulful rendering of "When a Man Loves a Woman" was particularly impressive -- her delicately husky voice wrapped itself around the high background harmonies of her partners.

If there is a problem with the Starland Vocal Band, it is that the group never takes any chances. The material and its presentation are polished, yet predictable, and the singers are technically adept, yet squander their abilities on a show that is pleasing but never thrilling. Still, the group manages to entertain, and sometimes that is enough.