CD. Forty-five minutes, composed in 2020 for a small orchestra of brass and woodwind built or adapted for the purpose, and tuned to Meta-Slendro, a seventeen-pitch scale devised by Erv Wilson. Wilson is the name sitting under half of American microtonal music of the last fifty years and almost never on a sleeve: tuning theorist, draughtsman of harmonic lattices, correspondent of anyone working on the problem. Kraig Grady met him in 1975 and stopped composing any other way, moving from thirty-one tone equal temperament to just intonation built on Wilson's combination product sets. The line he works in runs back through Harry Partch and Lou Harrison.

The title reads two ways. One is geological and structural, a monument meant to last. The other is technical: diamonds are shapes that appear inside the tuning itself once the intervals are laid out as a lattice, the same geometry that gives Partch's tonality diamond its name. Across the forty-five minutes the music keeps a ritual pace, textures folding over slowly, overtones gathering and dissolving and coming back. Against the rest of the Another Timbre catalogue what stands out is the physicality of the brass, which gives the piece an almost architectural weight.

Grady, born in California in 1952 and long resident in Australia, declares himself a citizen of Anaphoria, an imaginary island whose North American embassy he has run since 1993 and for which he has written thirteen shadow plays. David Toop has called him an ethnographic surrealist. The invented geography and the invented tunings are the same operation carried out twice.