Midway through his trio show at the Rams Head Tavern in Annapolis on Thursday night, singer and multi-instrumentalist Tim O'Brien revealed his T-shirt, emblazoned with the slogan "Sex, Drugs and Flatt and Scruggs." But his affection for bluegrass was already obvious, as it sparked some terrific string band interplay and soaring harmonies.

Over the course of an hour and a half, O'Brien, fiddler Casey Driessen and guitarist John Doyle -- with a big assist from guest bassist and banjoist Mark Schatz -- cut a wide swath through homegrown and Celtic music. O'Brien led the way, playing mandolin, bouzouki and fiddle with effortless verve, and often singing in a soulful, unaffected fashion. Tunes from "Traveler," O'Brien's recent CD, were frequently showcased, and they revealed his often overlooked gift for songwriting. Doyle, an Irishman with a tenor voice well suited to traditional ballads, complemented the original songs with a lovely rendition of "The Sea-Apprentice Boy." Sparks flew, however, during a stirring rendition of Bob Dylan's "Senor," a freewheeling take on "Jack O' Diamonds" and some reeling twin-fiddle tunes that prompted members of Footworks, a local dance ensemble, to kick up their heels at the edge of the crowded stage. Still, the up-tempo tunes weren't the only thing to get a rise out of the audience. O'Brien roasted the Bush administration to the tune of "High Heel Sneakers," and tossed in some surefire musician jokes for good measure. To wit: "What do you call a beautiful woman on the arm of banjo player? A tattoo."

-- Mike Joyce