Song Struck : Career: Actor Woody Harrelson comes out from behind the bar where everybody knows his name and returns to his first love--music.

Woody Harrelson has a vivid recollection of the moment he was bitten by the bug. And it wasn’t, as one might rightly assume, an insect of the acting variety.

“The first time I performed music in public was in the high school library in Lebanon, Ohio,” the affable Harrelson said in a phone interview Monday. “A bunch of guys said, ‘Hey, do the Elvis thing.’ So, I hopped up on a table and did my rendition of ‘All Shook Up.’ ”

The actor sings a credible few bars over the line before resuming his story. “Everyone in the library seemed to be so into it that I just went crazy. I knew right then that this was something I’d want to do more of.”

And thus was the groundwork laid for Manly Moondog--the singing, songwriting alter ego Harrelson will bring to the Belly Up Tavern Friday night for the San Diego debut of his 10-piece band called the Three Kool Kats, whose music combines elements of rockabilly, topical folk, and R&B.;

Only those without a television would not know that Harrelson, 30, plays the role of the lovable naif, Woody Boyd, the bartender on the popular television sitcom, “Cheers.” He’s even won an Emmy for his work on the show. In fact, millions of people so inextricably identify one Woody with the other as to remain unswayed by Harrelson’s very different characterizations in such feature films as “L.A. Story” and “Doc Hollywood,” or even by his informed, articulate, and much-publicized stand against the Persian Gulf War.

Now, however, the actor is asking people to accept him in the real-life roles of singer, performer, and bandleader, and he realizes that will take a Herculean selling job.

“Music was always something I wanted to do, it’s always been cooking right below the surface,” he said. “But then once I landed the ‘Cheers’ role and got famous for that, I felt that people wouldn’t take my music thing seriously, which is understandable.

“Still, I was determined to get into music somehow. For a while, I considered doing a ‘Pinball’--you know, the Jerzy Kosinski thing, where I could be completely anonymous. But, eventually, I decided to be myself, more or less, to be so passionate about the music that it would overcome any preconceptions. And, so far, things have been going pretty well.’ ”

In the face of weighty evidence that acting is his true calling, Harrelson, who was born in Midland, Texas, and raised there and in Ohio, contends that music has had the longest and strongest hold on him. At age 11, he foreshadowed both his political bent and his interest in music when he wrote a song called “Better World.” Recently, Harrelson exhumed and contemporized the song, which has become part of his repertoire.

“I started really listening to music pretty early, when I was 6 or 7,” he recalled. “You know, Beatles, Monkees, and whatever. Then, when I got into my teens, I started listening to Elvis. This was after he died. I started singing his songs, and I’d sing them on the high school football bus and the other players would get into it. I didn’t really do an Elvis impersonation, per se, I’d just sing his songs.”

Harrelson’s campus renown as the resident Elvis inevitably led to the impromptu library performance, which, in turn, led to the incident that would change his life.

“Word got around that this maniac had sung Elvis in the library, and soon after that, a girl in the theater department suggested that I try out for a school play,” he remembered. “I won a part in ‘Six Characters in Search of an Author,’ by Pirandello. Kind of a heady work for a high school senior, but I dug it, so I kept doing theater.”

Harrelson continued acting at Hanover College in Indiana, but he also learned how to play piano, and before long music once again had become a near-obsession. He started writing songs, a preoccupation that would continue even after he moved to New York City to find work as an actor.

“For a long time when I was living in New York, nothing was happening with the acting stuff, so a roommate and I would write songs and play them at parties,” Harrelson said. “I loved it. It’s just such a fantasy to get up and sing in front of people. I think everybody’s a shower singer, or sings in the car. Just look around while you’re driving.”

While Harrelson still was living in the Big Apple, Neil Simon himself recommended him for a part in the Broadway production of Simon’s “Biloxi Blues.” His acting career took off, but even after he got his big break on the “Cheers” series, Harrelson wouldn’t relinquish his secret ambition.

“Once I became this famous TV guy, I didn’t know how to go about being a musician again,” he said. “Then about a year and a half ago, I was speaking at Southern Illinois University, and I went to a club called the Hangar. A guy in the band announced that I was there and, not even knowing if I was capable of it, asked if I wanted to get up and sing something with them. I asked them if they did any Elvis, and they said they did ‘Jailhouse Rock.’ Well, it was more fun than anything I’d ever done. The overall synergy between me, the audience and the band was so exciting that when I left I said, ‘I have to get a band together.’ ”

The result of his efforts was Manly Moondog and the Three Kool Kats, an outfit made up mostly of L.A. session players, and featuring Harrelson on vocals. Harrelson’s frequent songwriting collaborator, guitarist Alfons Kettner, is the band’s musical director. The group debuted at L.A.’s infamous China Club in the fall of 1990.

Harrelson, who includes Paul Simon, Rickie Lee Jones, Cat Stevens, Van Morrison, and Bob Marley among his musical influences, wrote the words and music to about half of the Kats’ material. Kettner wrote the music and Harrelson the lyrics to the rest of the band’s song list.

The group has performed more than a dozen shows on its current tour, and while Harrelson admits that some shows are better than others, he is more than satisfied with the way things are developing. It therefore comes as something of a surprise when he contends that he has no immediate plans to enter a recording studio.

“At this point, I’m not even thinking about a record deal,” he said. “I’m just so excited performing the music. I’m doing this for the enjoyment. It’s been phenomenal. Yesterday (Sunday), in Fort Lauderdale, I had one of the most exhilarating experiences I’ve ever had when we played to 5,000 people in a huge, tented area. By the time we get to San Diego, we should have a full head of steam.”

Manly Moondog and the Three Kool Kats featuring Woody Harrelson perform at the Belly Up Tavern in Solana Beach on Friday. Opening the 9:15 p.m. show are Jerry McCann and the Band of Giants. For more information, call 481-9022.