Comment by mbrameld

> 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).

I don't think intervals are unique to trombones. If you understand that X+1 is a half step above X, and you know note X is 1st valve and note X+1 is 1+2, then you know adding 2-to-1 adds a half step even if you've never seen a trombone.