Channa Horwitz and Haroon Mirza at Ghebaly Gallery, Los Angeles

Standing in Haroon Mirza’s sound installation, lengthily titled A Chamber for Horwitz: Sonakinatography Transcriptions in Surround Sound (2015), one has the sense of being in a darkened arcade. Initially shown at the Museum Tinguely in Basel and now at Ghebaly Gallery in downtown Los Angeles, the chamber features soft black carpeting and contains eight narrow “sound devices”—speakers with blinking LEDs along their top edge, arranged between tall puzzle-like assemblages composed of speckled foam wedges. The devices emit low, drone-like sounds that shift register slightly and last for varying lengths of time. When a note shifts, the LEDs change color. Medium-green notes last the longest. The whole composition continues for 13 minutes and 26 seconds, and has a hip, intoxicating vibe. The foam wedges, confidently jutting out from the walls, have something techy and clever about them. They’re the kind of design objects committed nerds might gravitate toward after graduating from their mother’s basement into a sleek Silicon Valley office.

Mirza, consistently interested in relationships between sculpture and sound, took his inspiration for this chamber from the work of longtime L.A. artist Channa Horwitz, and his exhibition at Ghebaly coincides with her much larger second solo show at the gallery. The Horwitz score that he “transcribed” hangs right outside his chamber. It’s a meticulous grid delicately painted on five and a half feet of Mylar, color-coded so that certain colors represent greater or lesser lengths of time. Horwitz, who did this particular drawing in 1996, had a significantly different career trajectory from that of the London-based Mirza, now in his late 30s and already the recipient of a number of art prizes (the Calder Prize, the Venice Biennale’s Silver Lion). When Horwitz passed away, in 2013, she had just been included in her first biennial, received her first major fellowship—a Guggenheim—and opened her first solo show at Ghebaly Gallery. Certainly, she had exhibited throughout her career, but the concentrated, mainstream art-world attention to her work had reached a high point.

Horwitz, who’d dropped out of art school in the 1950s to start a family and then returned to art making in the later 1960s, developed her Sonakinotagraphy notation system around 1968. According to the system, eight entities move across eight-by-eight graph-paper squares. In a 2010 interview Horwitz described coming up with this system while on vacation with her husband. She excused herself from a tennis match and went to her hotel room with graph paper and colored pencil, feeling elated when she realized she could convey a sense of motion and shifting sound just by rearranging squares and colors.

It’s difficult to know how much stories like this—including one about her exclusion from LACMA’s all-male Art and Technology initiative in the early 1970s—affect the way her work reads now. Without such background, her approach to grids might read as trendily minimal. However, at Ghebaly Gallery, her drawings, all modestly sized and spread throughout three rooms, come across as solitary, committed, and precious, almost eccentric in their precision. Her “Variation and Inversion on a Rhythm” series (1975–76) shows a line of tall rectangles that gradually shift their arrangement and shape, some leaning into others, becoming narrower and moving from one side of a page to the other. In Eight (n.d.), a study, eight chambers of eight stacked rectangles stand in a line, morphing from left to right and gradually unraveling, until they’ve expanded into an oddly shaped form that recalls a space-age portal.

Experiencing Mirza’s work alongside Horwitz’s underscores a significant contrast. His appropriation of her obsessive system feels so obviously valid, bold, and easily immersive. Her work, at every turn, seems to insist on its right to exist. The artists’ interests overlap deeply, as do their formal sensibilities, but they’re of different moments, and so their work radiates very different energies.