Looks like part of a fireplace grate or something that goes on a railroad track

Have you read / played Yusef Lateef’a Repository of Scales and Melodic Patterns? That chart is reproduced in the book. yuseflateef.com/store/index....

Are you familiar with Jim Marshall’s work? “Show Me the Picture,” (film doc about JM). He photographed Miles Davis boxing, John Coltrane in Berkeley jimmarshallphotographyllc.com/node/13