A Night of Varied Beats : Latin music sensation Selena is a real and likable presence as she mixes <i> Tejano, cumbia </i> and <i> ranchera </i> styles in concert.

Years before topping the charts and becoming one of the major stars of the Latin pop music world in the United States and north of Mexico, Selena was already a hometown sensation in the Tejano clubs of Corpus Christi, Tex. Thursday night at the Universal Amphitheatre, her first major Los Angeles concert, she showed why and left the impression she’ll be around for some time.

As in the case of other acts that grew beyond the Tex-Mex circuit such as mega-seller La Mafia, it is clear that keeping the Tejano tradition intact is not one of Selena’s priorities. Her pop, cumbia -flavored style inevitably gave her a mainstream audience and, at this show, even the regional numbers seemed middle of the road and lacking in the power and edge that’s a trademark of the style. The biggest problem was that her eight-piece band, Los Dinos (including the solid presence of sister Suzette Quintanilla on drums), wasn’t explosive enough to keep up with the singer.

Selena, 23, whose 1993 “Live” recording won a Grammy for best Mexican American album, is not an outstanding vocalist or dancer, but few Latin stars today are able to jump from Tejano styles to romantic ballads to cumbia and even a ranchera with her ease and credibility. Her dancing, limited to easy pirouettes and shuffle-stepping, is only part of a charming package that had the audience on its feet from the opening song.

Selena is the ultimate girl next-door--beautiful, but in a simple, down-to-earth way--while her voice sounds like many found in dark restaurants throughout Latin America and, every time she spoke Thursday--in vastly improved Spanish (English is her first language)--she sounded truly likable and real , not a common characteristic in most Latino mainstream acts.

On that count, there was only one big mistake in the show: her out-of-place onstage pitch for a shampoo that sponsors her. Selena’s primary appeal comes from her simplicity and authenticity, and as long as she sticks with that her validity will be secure.