If it was your first time, you stood in the dimly lit back room of Gallagher's Pub among scattered guitar cases and tattered lyric sheets, fingering a cigarette or clutching a mug of beer and you waited -- first for the applause for the performer ahead of you, then for the shakes, and finally for your name to be called.

"I was terrified," David Wiegand, 35, said Sunday night, recalling the first time he sang and played guitar in public at the Cleveland Park bar. "I never even went to an open mike before here."

Gallagher's, 3319 Connecticut Ave. NW, sets aside Sunday and Monday nights for the showcases. Its Sunday night event, lately conducted by singer-songwriter-guitarist Steve Erwin, is perhaps the strongest of them all.

"We've played a couple of different places but this is our favorite place," David Stinson, 27, said while he and Wiegand tuned their guitars in the back room.

"It's got character," Wiegand, Stinson's "cousin-in-law" agreed.

David and David, both of whom are trial lawyers at the Justice Department, have been playing together for about two years and first played publicly at Gallagher's.

"The first time we played we were really nervous," Wiegand said.

"Now it's fun," Stinson said.

"We play our three songs, sit down," Wiegand said, and then they root for the other performers. "Everyone is supportive of each other," he said of the congenial mix of working musicians, amateurs, would-be and soon-to-be stars who are as likely to be priests as clerks in a natural food store.

It's Erwin's job to organize performances -- usually there's enough time for about 15 three-song sets -- and to position microphones and adjust amplification systems on the public address system for each.

The music played, Erwin said, runs "across the board" and though bagpipes, keyboards, horns and other instruments. Most performers accompany voices with six-string guitars.

"Buy one today. Amaze your friends," Erwin pitches.

"Whether it's jazz or rock or a country songwriter or whatever," Erwin said, "the audience comes to see these people. There's a real supportive feeling for people who are on stage."

The support is there because -- besides the musicians who are there to perform -- there are always more musicians who come to hang out, jam in the backroom and listen along with other patrons.

"It can be a real tough audience," Bill Koerner said from his seat at the bar, "because the audience here is used to real good music." But the musicians, he said, "help each other out" with advice about a lyric, praise for a melody or a simple: "Hey, that was a nice song."

Koerner, 40, was the bar's night manager for 11 years before leaving last year to take a day job. "I've seen some people get intimidated," he said. "Some freshmen or sophomore from college who strums guitar comes in and thinks it's going to be like sitting in his dorm room," Koerner said. "I've seen them say, 'Uh oh. I don't want to play' " after hearing the quality of some players. But the same players, he said, will "show you no one is ever going to laugh at you."

Koerner, as does most anyone in Gallagher's, points to Mary Chapin Carpenter, who conducted the Sunday night open mike before Erwin. Carpenter, who has been working at her music for more than 10 years, recently released her first album "Hometown Girl" as part of a national record deal. "I remember when she first came in here as a young student at Brown" University, Koerner said. "She had a lot of help from other musicians who played here."

Criticism and support are what have kept Paige Powell coming to Gallagher's from Adelphi. "I'm a songwriter," the 35-year-old technical illustrator said. "If someone from the audience says, 'I like the second one best,' or the third one {the feedback helps me} work out the kinks in my songwriting. When you gig, you don't get to talk to other musicians."

Or praise them, Powell said, but "George brings the house down."

George Hardman, 39, a U.S. Capitol Police officer seated across from Powell at a table, grinned. "I have my nights," he said.

Hardman was encouraged to play open mikes at Gallagher's about a year ago by fellow members of a folk group at Holy Redeemer Church in Kensington. "I fell in love with the place," Hardman said. "It's like right out of a fantasy. Gallagher's can be your Carnegie Hall or whatever you want it to be."

"Everybody in this room has wicked fantasies," Drew Holland said after he and Melinda Root wound harmonies around a Hank Williams' standard tighter than a western boot. "You're the guy who ends up in the kitchen {at parties} playing guitar," Holland said. "After a while you play an open mike; it's just great. There's no manager with a big fat cigar."

Holland and Root met at an open mike at Whitey's in Arlington and although they now play some paid gigs with a rhythm section they picked up at Gallagher's, they essentially play for one reason:

"If it's not fun we don't want it," Holland said.

Root, who was once worked in a top 40 band, agreed. Singing full time, she said, "wasn't much fun at all. It was a job and I never want it to be a job again." But, she said, Gallagher's low pressure open mike provides an opportunity for "people who really deserve a chance to play in front of an audience. It's like those movies with Mickey Rooney going, 'I know, let's have a show.' "

Just a week before, Holland said, a couple dragged a friend out of the audience to sing some doo-wop. "It surprised the hell out of him," Holland said. "People were going crazy, he was dumbfounded and this was all in the space of 15 minutes."

"Every open mike has that possibility," Erwin said.

Sunday night, Erwin was accompanied under blue and red lights by Jeff Felsher's jazz-honed guitar leads and fills and Felsher followed with his own set. Rob Guttenberg, whose guitar playing helped him recover motor skills damaged three years ago in a stroke, finished with the self-penned "Living Everyday." David and David called Guttenberg up for a harmony assist on a Rolling Stones song. And David Stinson called out, "Hey George," from the audience.

"Hey Dave," George Hardman called back. "Yes, it's by Elvis," Gallagher's own rock'n'rollboogiebluesman said before striking a rocket-legged, quiver-hipped pose and yelping: "One Night With You."

And so it went -- each performer telling it like it is for similar but personalized reasons -- until the midnight hour when Erwin and Felsher returned to the stage.

"What I like," Erwin said, "is the ability for someone to state something that seems to be real and true in a way that another person recognizes . . . . You feel a change in the room, it's a narcotic, no question about it. Once that happens you want it again."