I loved playing trombone in school. It's such a simple mechanism, it invites a lot of curiousity, and this piece captures that well. Instruments like piano, violin, and guitar are very visual, essentially wysiwyg. Instruments like saxophones, clarinets, flutes, take a long to mentally map and reason through (this combination of keys achieves note X). Trumpets, and other 3 valve instruments map exactly to trombone positions! Eg. no-valves = 1st position, 1st valve is 3rd position, 1+2 is 4th position. But visually you don't see this, and it doesn't invite the curiousity. Trombone super unique in that you get a little wysiwyg, but you have to square that with embouchure. But learning trombone, and then mapping that knowledge to a euphonium, trumpet, tuba, etc, gives you a knowledge about that instrument (eg ok if note X is 1st valve, and note X+1 is 1+2, then i know adding 2-to-1 adds a half step, because position 3 is a half step from position 4).