They’re younger than they sound

In the movie “Stand and Deliver,” you’ll recall, people could not believe that a class of Mexican American math students from Garfield High School in East Los Angeles could do so well on their college entrance tests. The authorities thought they were cheating because nobody from the barrio was expected to score so high.

If Thursday’s show at the Temple Bar in Santa Monica had been a test, the same thing might have happened to Upground, a brash young band that comes roaring out of the same school. Nobody would believe that musicians still so young could play with such command, power and sophistication. Especially not a band from the barrio.

In this case, you can’t blame the skeptics. It’s been a long time since East L.A. -- which gave us Tierra in the 1970s, Los Lobos in the ‘80s and Quetzal in the ‘90s -- has yielded a new pop group worth noting. The barrio should do better than one hot band per decade.

In the tradition of its Mexican American predecessors, Upground is musically grounded in two cultures. It stands out, however, with a fresh, exciting sound that fuses a wide array of upbeat influences, including swing, cumbia, reggae, jazz, ska and punk.

During Thursday’s one-hour blast of a set, they combined youthful exuberance with a maturity beyond their years. This band is so young that some members weren’t allowed to remain in the club after they left the stage. The youngest, trombonist Joe Quinones, 16, had final exams the following day at Garfield, where he still plays in the marching band. Six of the other seven musicians -- the oldest 22 -- previously attended Garfield.

Despite their age, they seem to channel artists many of their peers have never heard of -- Bob Marley, Glenn Miller, Arturo Sandoval, Tower of Power. And they play with a surprising mastery of complex harmonies and time changes.

The band has recorded a five-song EP that doesn’t do justice to its members’ abilities. (A full-length new album is due soon.) Upground has to be seen and heard live to be fully appreciated.

Here’s a band with personality. It boasts a charismatic frontman in Danny Estrada, who delivers growling lead vocals and mean licks on lead guitar. Co-vocalist Everardo Garcia offers soaring trumpet solos and does arranging for the precise and muscular horn section, rounded out by Eric Carrillo, Chris De Los Santos and Aaron Perez on saxophones. Adolfo Mercado Jr. is a tireless piston on drums, pumped up by Chris “Bolillo” Manjarrez’s taut bass. Several are multi-instrumentalists, rotating on stage among horns, timbales and keyboard.

It’s obvious from their demeanor that they like what they’re doing, and their enjoyment is contagious. In “Night Stick No,” a hard-driving plea against police brutality, they exploded in a choreographed riot of rhythm and wailing horns. By the end, they had fans hopping and jumping for joy.

Stand and deliver, indeed.