THE CLUE was in the type fonts. Because of the design of its ads, the Irish bar Paddy Mac's (8241 Georgia Ave., Silver Spring; 301/608-3360) was catching people's eyes. I began getting calls from folks asking, "Is Paddy Mac's the return of Twist & Shout?"

"I guess those ads were a good idea," says Marc Gretschel, former owner of Bethesda's defunct Twist & Shout club and designer of the Paddy Mac's ads that mimic the look of those of his old club. "We wanted to let people know we're bringing some of that music back." In the months after Twist &Shout's 1998 closing, Gretschel stayed on the scene by booking blues, zydeco and rockabilly bands in places such as Chief Ike's Mambo Room and Chick Hall's Surf Club. But he still wanted a steady venue for his bookings, preferably one near his Silver Spring home.

"I dropped into Paddy Mac's one night and was introduced to the owners," Gretschel says. "We started to chat and it turned out they needed somebody to book bands in there besides the Irish stuff. We agreed that I should. I bring my kinds of things in there on weekends, and some weeknights sprinkled here and there, and they'll take care of Irish music on other nights and the Irish jam sessions on Sundays."

It's a formula that seems to be working, a happy surprise since Gretschel's involvement with the bar began in the middle of the summer's traditional doldrums. Folks have definitely been discovering the joint (which can hold nearly 200 people) and have made tracks to see national acts like Walter "Wolfman" Washington, the Mollys and Wayne Hancock. Paddy Mac's has also become a steady venue for local bands with rootsy inclinations like the Nighthawks, Bill Kirchen & Too Much Fun, the Hula Monsters and Ruthie & the Wranglers.

Rhonda Newsome, one of Paddy Mac's co-owners, felt that bringing in Gretschel to book music would help expand her clientele. "When we opened in October 1998, we started by having Irish music four nights a week," she says. "But the people weren't really coming out. Our Irish jam sessions on Sunday were always really crowded, but other nights weren't. What Marc is doing is really helping us out, and I love the music."

Newsome, a mortgage banker, decided to get into the bar business after missing the hectic days when she used to manage clubs and restaurants. "I always wanted to own my own place, and even though the hours are crazy, I'm loving it." She had developed an affinity for Irish pubs when she played professional basketball in Tralee, Ireland, from 1984 to 1986. "They were part of the landscape, a wonderful social environment where everybody went and talked and listened to music. I thought it would be nice to have one of those in Silver Spring, because that's where I'm from and no matter where I go I always come back here."

Paddy Mac's is a comfortable space, named for the father of Newsome's partner, Valerie McDonnell. The room is slightly tapered at the stage end, where it overlooks Georgia Avenue. But there are problems at Paddy Mac's: Sound quality that varies from band to band as they bring in their own p.a. systems; incredibly slow bar service (the waitress sympathetically rolled her eyes and shrugged when she saw how long I'd been waiting to catch the bartender's attention one night); and awful decor that ruins so many Irish bars. You know what I'm talking about: cardboard cutout shamrocks with beer logos on them everywhere you turn. Posters of doors of Dublin pubs. There is some nice, genuine Irish miscellany along the hallway toward the game room in back, but too late. The tacky commercial stuff has already spoiled things. Give me a blank wall.

Those annoyances aside, the only real problem with Paddy Mac's is that it's hard to find. It's on the second floor of a modern-looking three-story building at the corner of Thayer and Georgia, and unless you know just where you're going, you're not likely to stumble on it. But it's worth searching out, given the high quality of music you're likely to hear there.

This weekend you've got three fine nights of music. Tom Principato on Friday, fellow blues guitarist Bobby Radcliff on Saturday and Austin's swing combo the Hot Club of Cowtown on Sunday night.

PRINCIPATO STILL KICKIN'

Blues guitarist Tom Principato's show at Paddy Mac's Friday is a CD-release celebration for his new recording, "Live and Kickin'." And if you miss the Friday show in Silver Spring, head across the river Saturday night to Falls Church for another performance by Principato and his band at the State Theatre (220 N. Washington St; 703/237-0300). "I love the fact that we're having this concert at the State," Principato says, "because I used to go see movies there when I was a kid."

Wherever you catch him, you'll hear what Principato has wanted to capture on tape for a long time: the energy of a live concert. "Even though I've done most of my other records pretty much live in the studio, I miss the interaction with the audience," says Principato, who has seven studio recordings to his name. "But also I wanted to capture this version of the band playing this repertoire, and also it was important to me to capture the sound of the guitar when I play it live. For lots of reasons, it's just not the same as what I sound like in the studio."

On "Live and Kickin' " you can clearly hear Principato stretching out, egged on by his musical partners John Perry (bass) and ElTorro Gamble (drums). He's also distinctly fired up by the crowds that can be heard pushing him to go even farther, as they have for more than 20 years of his playing in the Washington area. The song selection is something of a "Principato's Greatest Hits," with lots of fan favorites, says Principato, "but they're really some of my absolute favorites, too." Eight of the 10 songs on the CD are originals, and they're ordered along the lines of an actual set, though the recording was done at two different concerts, edited together in the mixing studio.

Half of the CD was recorded at the Kitty Hawk Grill in Ocean City, a small club that's more like a comfortable beach house than a full-blown rock club. The other half was recorded a world away in Slovenia this past April. "We did a concert in a very swanky gambling casino there in the capital city," says Principato, "and they were recording it for broadcast on the radio. I knew we were playing well, and when they sent me a tape of the concert, it was obvious that we had the rest of the record."

Principato says he'd be happy if this latest release brought him widespread fame and fortune, but he's happy at the level he's reached. "I have a definite niche at this point in my career," says the 47-year-old. "I sell about 10,000 CDs a year, I get to tour Europe a few times a year, and while the club scene in the U.S. is nothing like what it used to be for my kind of music, I'm so lucky to be able to make a living doing what I really love."

For the CD-release concerts, the Tom Principato Band will be joined by percussionist Gali Sanchez. For more information on Principato, his recordings and his concerts, check out www.tomprincipato.com.