The Quadrangularis Reversum is best described as which of the following?

The story behind the answer

The Quadrangularis Reversum is a percussion instrument—specifically, a custom mallet instrument created by American composer-inventor Harry Partch to perform his 43-tone just intonation scale. It resembles a marimba but uses a striking mirrored, four-sided (quadrangular) layout of wooden bars, producing shimmering, microtonal sonorities central to Partch’s theatrical and ritualistic music.

Partch built families of instruments so players could physically “see” his tuning system. The Quadrangularis Reversum complements his Diamond Marimba—the “reversum” signals its mirror-image design. Memory tip: “Quadrangularis” = four-sided array of bars; “Reversum” = reversed/mirrored—think “a marimba turned inside out.”