Federal Jazz Project sweeps from 1939 to present with a Latin-jazz vibe: frontal, hot, eloquent.

The good news about the Rep’s Federal Jazz Project: music lovers unfamiliar with the name Gilbert Castellanos are in for a surprise, maybe even an epiphany. The San Diegan’s a world-class trumpet player who can make that horn blare or mist, blitz or bleed, with astonishing precision. He hits notes inside grace-notes without effort, it would seem, as if just chatting with friends. And the talk is two-way: his gift evokes the musician in you. You’ll nod, tap a foot, make spontaneous twitches, anything to contribute your fair share. Don’t believe me? Check out his “Squatty Roo” on YouTube and chat with a master.

In 1998, Castellanos jammed at El Campo Ruse, at 16th and Broadway. Richard Montoya of Culture Clash heard about the late-night sessions and went to the former art gallery. He was surprised that some musicians were in the military and headed back to the base in the wee hours. Castellanos, however, was no surprise. His reputation preceded him. Montoya vowed then to write a piece that included them both and that told the largely untold story of the local jazz scene through the years and its Latino roots.

The difficult news: Federal Jazz Project, in its world premiere, currently exceeds its grasp. It sweeps from 1939 to the present, with overlong scenes, stencil-thin characters, and narrative intrusions (some poetic or funny, others just there), and Castellanos isn’t featured enough. The piece combines music, drama, videos, dance sequences, monologues, and only one instance where the first-rate band gets to cut loose. It unfolds like an overly ambitious outline. Only the music and Victoria Petrovich’s excellent videos of old San Diego feel properly sketched in.

The first image is the most arresting. Montoya enters, dressed like Philip Marlowe, and crosses a stage straight out of film noir. Christina Wright’s steep, mystical lighting casts telling shadows on a wooden desk. Castellanos appears from the darkness playing a soft background — like a warming fog, if such were possible — and Montoya reads from a script. He’s a guide, in the basement of the El Cortez Hotel, leading us farther underground, through a labyrinth of halls and doors, and back in time. We arrive, as if down a rabbit hole, in a free zone before, Montoya says of Latinos, “we were unholy.”

Ceiling-high bunches of dark cloth flop to the floor. Suddenly we’re in “South of Broadway,” a brick-walled jazz club on the outskirts of the old Stingaree, and Castellanos and crew are bebopping: frontal, hot, eloquent. That moment, that lurch as if from Kansas to Oz, is magical.

The main story, however, is not. Sally (versatile Mark Pinter) owns the joint and needs to replace his lead act. Enter Kidd (Joe Hernandez-Kolski) with talented sisters: San Diego (Lorraine Castellanos) sings and plays guitar; Tijuana (Claudia Gomez) tap dances. The sisters carry an allegorical burden: they represent the un-twin border cites. But neither they nor Kidd have any depth or inner lives. They exist, more often than not, just to prove a point — about racism, unpraised Latino war heroes, McCarthy witch-hunt hearings in Logan Heights (à la Luisa Moreno and KKK-hounded Roberto Galvan). Everything they point out matters and may open up unknown San Diego history the way the piece introduces Castellanos. But the characters are pawns. We see them over the years but never know them. That the sisters must also stand for cities muddles more than clarifies.

The time-traveling, free-zone premise allows Montoya to inject various kinds of storytelling into his narrative. Two monologues stand out. Keith Jefferson enters in uniform. His name is Jules and he talks about returning after World War II and only able to buy a house at Woodlawn Park. Jules is African-American. The Otay neighborhood, in those days, was known as N-word Hill.

Four mustachioed men, who have been making scene changes and playing Sally’s henchmen, come forward. Montoya does his best writing about them: “Las Rafas” (the “supports,” “buttresses”?). Just down the street from El Campo Ruse, Los Cabrones had a motorcycle club. The stagehands were members back when Montoya heard Castellanos play. It’s a wonderful moment. As in A Chorus Line, four largely unnoticed men moving props in semidarkness stand center-stage and become living San Diego history. The speech transforms them into hip, code-honoring insiders con respecto.

Castellanos is a San Diego icon (his original score traces jazz from boogie and hard-bop to Cuban-Mexican danzón and more contemporary styles). So is multitalented Montoya, whose group, Culture Clash, has entertained and educated Rep audiences for decades. But in many ways, Federal Jazz Project is about him. As El Poeta, he controls the narrative, intervenes, and comments (often name-dropping — and stereotyping — local cities: El Cajon, hardy-har, “go back to Fallbrook”). In effect, his narrative does much more telling than showing. If he were a point guard, he takes too many shots and needs to drop more dimes on his teammates, the remarkable Castellanos most of all. ■

Federal Jazz Project, by Richard Montoya, music “composed and curated” by Gilbert Castellanos

San Diego Repertory Theatre, 79 Horton Plaza, downtown

Directed by Sam Woodhouse; cast: Richard Montoya, Mark Pinter, Joe Hernandez-Kolski, Claudia Gomez, Lorraine Castellanos, Keith Jefferson; scenic design, Robin Sanford Roberts; costumes, Christina Wright; lighting, Lonnie Alcaraz; sound, Tom Jones

Playing through May 5; Thursday through Saturday at 8:00 p.m. Matinee Sunday at 2:00 p.m. 619-544-1000