BROCK WALSH came to Harvard to play soccer, but there are some people in California betting that he ends up a rock and roll star. In August, Walsh, a junior in Adams House, hitchhiked to Hollywood, where he met his manager and auditioned for Columbia Records. They expect to sign him within two weeks.

"If it hadn't been for soccer, I'd never have thought of applying here," Walsh says now. In early April of his senior year in high school, just after he was listed as a high school, just after he was listed as a high school all-American, he wrote to Harvard asking if it was too late to apply. In most cases, it would have been, but by April 15 he was accepted. Since then, Walsh has only played J.V. soccer ("which means I show up the day of the game") but his musical career has blossomed.

Walsh has been playing concerts and engagements in nightclubs for almost three years, but he only recently made a serious effort to market his music. The summer before he came to Harvard he made a tape and played it for a record company in New York. "They gave me a lot of hype, but they never called back."

Last winter, on the advice of a friend, Walsh sent a tape made in an Adams House practice room to some New York managers rather than directly to record companies. This time two managers responded favorably, and by mid-summer he had signed with one of them, who arranged the August audition.

Most of Walsh's concert experience was garnered in three summers at the Last Chance nightclub in Poughkeepsie, New York, his home town. At the Last Chance, Walsh played one summer alone, once with his own band, and once as a small part of a dixieland band. This band featured Johnny Windhurst, a trumpet player who is considered one of the best Dixieland performers and said to be the only man alive who can play "West End Blues." "I had no business playing with him," Walsh admits. "I was just a honky--but the experience taught me a lot."

He learned much of his craft at the Last Chance, and the take from the gate paid part of his tuition. Playing at the club gave him an opportunity to develop an easy stage rapport. "I consider working with audiences an education," he said. "You have to learn the ability to adapt yourself to different types of people." But the nightclub environment became stifling. "I was becoming Brock Walsh the live jukebox. All people wanted to hear was Elton John. That was the least dangerous stuff to do, if you didn't want to offend anybody."

Walsh's own songs are mostly quiet folk music accompanied by guitar and, occasionally, piano. His lyrics tell of love stories, country scenes and fantasies. When he first tried to do his own songs at the Last Chance, he met with resistance. "We were drawing the wrong type of clientele. People would walk in and say. "What is this? Bring back Elton John!" But slowly, he built an audience, and the club's attendance climbed.

ALTHOUGH his music does not reflect them, the performers that Walsh claims have influenced him most are the Beatles and Randy Newman. As his writing matures, Walsh is getting away from the simple themes and lyrics which mark his early songs. The open sentiment, simplicity of arrangement and occasional religious imagery are giving way to the sophistication of more complicated arrangements and more considered, sometimes cynical, lyrics.

"Randy Newman's songs have convinced me that music isn't necessarily a totally spontaneous experience," he says. "Stylistically, you won't find much Randy Newman in my songs, but he's made me become more careful lyrically."

Walsh has mixed feeling about Harvard. "I have a good time here, and a lot of my friends are at Harvard--that's very important for writing. But I can't stay here too long."

There are other advantages to being at Harvard. "Boston is a great place to break a band," Walsh claims, "because of the great number of students, and people who are interested in the arts and the great radio promotion that's available. The only other place that is comparable is Los Angeles." Walsh has played concerts at Currier House, Wellesley and the Good Life coffee house at the Hotel Continental. He plans to do an Adams House concert and appear at Passim's.

But at Harvard, Walsh feels "detached" from what he wants to do most. "This place is very narrow, as big as it is," he says. Nonetheless, his managers are encouraging him to stay in school to complete his education--and being a Harvard student "does no harm for publicity."

Walsh complains of an "artist" syndrome, which he finds in the record industry, and also at Harvard. '"Artist' is the word they use in contracts. These are people who indulge themselves thinking that the 'gift of creativity' somehow elevates them, and makes them more sensitive than other people," he complains.

As he becomes increasingly involved with the record business, he is meeting more 'artists,' and is becoming himself commercially conscious, now and then slipping into the jargon of managers and agents. Now that managers and the prospect of a record contract have entered his life, his concerns have become those of a professional musician.

Walsh is hopeful that he will not have trouble adapting his music for a popular market. "I think my music style is commercial," he says. "To many people, that's a dirty word, but I don't agree. If the stuff will sell, fine. I don't think I'll have to change my style to write AM hits."

Walsh criticizes "artists" who are not active in promoting their albums: "If the record company provides the promotion, they expect you to sing--push the product. "He hopes that he won't develop a stage character that is "too far from my own personality."

One accomodation that Walsh has already made is a minor one. His managers considered his name too short and too ordinary. They convinced him to use all three of his names--Brock Patrick Walsh--for his billing.

But Brock Walsh has made his decision, and he recognizes its finality. "I've made a choice--I'm going to sign a contract," he says. "I don't have any hopes of changing he business. I just hope that I can accomodate myself to the industry without sacrificing too much."