Until the success of the Texas nightclub that carries his name, country singer Mickey Gilley's career bounced up and down more than the mechanical bull in "Urban Cowboy."

During the '50s and '60s, the singer had been with more record labels than Mel Blanc has voices, little shots in the dark named Minor, Rex, Khoury, Lynn, Sabra, Princess, Astro. His first regional single, "Is It Wrong?" came out just as the label it was on went bankrupt.

"To tell you the truth, I had given up as far as my recording career was concerned," Gilley says, relaxing after his Thursday night concert at the Kennedy Center. "People told me I sounded too close to my cousin, Jerry Lee Lewis, and they didn't need two of us on the road. I didn't think that I was ever going to have a national hit."

But at 45, his albums are selling better and better, with "One in a Million" a recent No. 1 country single.Although Gilley's musical career has taken off since the release of "Urban Cowboy," his rollicking, boozy tunes and where-the-action-is honky-tonk have long been staples of Pasadena, a Houston suburb. He bought the club in 1971, when it was a ramshackle not-so-hot spot called Shelley's with a capacity of 750.

Over the years, Gilley and his partner/manager Sherwood Cryer have added so many wings that the place could almost fly away if it weren't weighed down by all the games, pool tables, bucking bulls and punching machines that have made it a combination circus and watering hole. Its 3,500-person capcity under 3.2 acres of roof make it, according to the Guinness Book of World Records, the world's largest nightclub. "It's like taking a baby and feeding it and letting it grow into a man," says Gilley in a proud Texas accent that seldom gets out of hand.

Gilley is not Texas-bred.He moved from Ferryday, La., when he was 17, and landed a construction job in Houston -- the same pattern that befell Bud, the central character in "Urban Cowboy." But John Travolta's travails were nothing compared to the rocky road Gilley himself has traveled since singing "I'll Fly Away" as a 13-year-old in his hometown Assembly of God Church with his two cousins, Jerry Lee Lewis and soon-to-be evangelist Jimmy Swaggart.

Some of Gilley's early gigs had capitalized of family ties. "On my first job in Lake Charles, La., [he was 19] I only knew six songs, had to play them over and over again. But they liked that Jerry Lee-style, pumping-piano sound. Nobody'd ever heard of Mickey Gilley, but they all knew Jerry Lee. I'd sit down and do 'Great Balls of Fire,' 'Whole Lotta Shakin',' 'High School Confidential' and if people had their backs turned, they thought it was him."

Over the years, Gilley has moved away from Lewis' influence, though their styles of piano are still cousin-close. He also doesn't see much of Swaggart, the gospel evangelist whose views on non-Christian music are ultra-reactionary. "We don't get into the music scene that heavy," Gilley laughs. "Last time he saw me, he said he was very proud of the fact that I was able to control the success I'm having -- but he was praying for me."

Gilley hasn't needed any help controlling his success. When he first bought his club, he also hosted a television show in Houston. "But I used to go in the recording studio just to keep something on the air locally." One day he rushed in to record "She Called Me Baby All Night Long," a song he and Lewis had sung growing up. But deejays flipped the single over and started playing "Roomful of Roses," which became his first No. 1 country hit.

"I used to go in the studio with the idea that this was going to be my last shot at the big time . . . sometimes, you try too hard. When I cut 'Roomful' I couldn't have cared less, spent an hour and half total in the studio. With the club, I didn't need records to survive and so I began to relax."

Gilley has recorded a score of albums since the mid-'60s, spawning such hits as "Overnight Sensation," "Don't the Girls All Look Better at Closing Time," "The Power of Positive Drinking" and "My Old Flame's Out Burnin' Another Honky Tonk Down." Always a second-stringer in country lineups, he became increasingly famous as Aaron Latham's story of Texas honky-tonk rituals moved from the pages of Esquire to the silver screen.

The only impact, Gilley insists, has been an increase in the club's business on off-nights; weekends have always been SRO affairs for appearances by all of the top stars in country music. And the club has become a novelty tourist attraction, drawing people from all over the world. "It's just given me a chance to live a little bit better." When he's not on the road, he still manages the club himself from his home in Pasadena where he lives with his wife Vivian, a stand-by-your-man woman who is also the president of his fan club.

Gilley, who tends to Urban Cowboy-style (blue jeans, Western shirts, cowboy hats and fancy boots) remembers the mid-'70s when he wore 40-pound sequined outfits: "The suit was a show in itself -- you could hang it out there on the stage and say, 'You all come look at the suit!' But I'm not trying to sell that damn suit, I'm trying to see Mickey Gilley." He certainly is: His fan club/newsletter lists 113 items for sale through Gilley's, ranging from T-shirts, records, belt buckles, bull-riding gloves, hat tacs, beer trays and Gilley's Beer neon signs to, well, a whole lot of mechanical bull -- El Toro, for a mere $7,495 (up $3,000 since a year ago). During the filming of "Urban Cowboy," Gilley bought the patent on the bull and now is fighting several companies that have put copies on the market.

Nonetheless, this year looks as bullish as 1980: In addition to hit albums and singles, he recently recorded a long-awaited duet album with Jerry Lee Lewis; he has four songs on the just-released second volume of the film's sound track; and network TV covered New Year's Eve from Gilley's. f

He only plays at his home base twice a year now, but it's obvious that he hasn't outgrown it. "It's fun," Gilley says, "it's honky-tonk, a joint. There's nothing fancy about Gilley's. If you look in the dictionary to find what honky-tonk is about, well, you're looking at one." Webster's defines it as "a cheap, disreputable, noisy cabaret or nightclub," and "that describes Gilley's just about as close as you could possibly describe it," Gilley insists, laughing all the way.