Freedom Set to a Loop Pedal

There is a moment early in “Mexodus” when Nygel D. Robinson pulls a live pattern from a double bass, then loops it into the foundation of a song, with Brian Quijada building on top of it. It happens again and again over the next ninety minutes, and it never stops working. This is a play that manufactures its own soundtrack onstage, without a break, without an orchestra pit, without a wasted second, and the mechanics of that feat turn out to be inseparable from the story it tells.

The show, which opened Sunday at Pasadena Playhouse, follows the roughly ten thousand enslaved people who fled not north but south in the mid-1800s, crossing Texas and the Rio Grande into a Mexico that had already abolished slavery. Quijada and Robinson wrote the piece together and perform it as a two-man company, trading instruments and narration with a fluency that erases any sense of a script being followed.

Robinson plays Henry, a freed slave still on the run from the law (It’s complicated). Quijada plays a Mexican rancher. Their bond forms slowly, through languages neither fully shares, and the friction of that exchange gives the play an added dollop of tension.

What sets “Mexodus” apart from Pasadena Playhouse’s recent run of well-intentioned, conventionally staged work, is the sheer nerve of its form. Quijada and Robinson use a floor full of looping pedals to construct hip-hop, gospel and folk textures from scratch, layer by layer, in view of the audience. A guitar riff becomes a heartbeat. A guitar becomes a shovel. A vocal run becomes a train whistle. The audience becomes a chorus. The music is not underscoring the history; it is the history, built the way an oral tradition would have carried it, one voice at a time.

Director David Mendizábal keeps the impressive staging spare enough that the looping never feels like a gimmick, and Riw Rakkulchon’s scenic design gives the two performers room to move between a Texas plantation and a Mexican ranch without a single set change breaking the rhythm. Mextly Couzin’s lighting shifts the mood by degree rather than by blackout, and Mikhail Fiksel’s sound design, the true architecture of the evening, probably deserves to be called a third character.

The show runs without intermission, and by design, there is nowhere to look away. That density is the point. Few musicals demand this much of two performers, and fewer still deliver this as completely.

“Mexodus” runs through August 2 at Pasadena Playhouse, 39 S. El Molino Ave. More information and tickets are available at pasadenaplayhouse.org.