For thorough immersion into music in all its glories, I think the ideal would not be a single- note melody instrument. I hasten to add that I'm not dissing them at all. It's just that a deeper appreciation of melody AND harmony would come from learning the piano or guitar, for example. Maybe in the ideal world you'd learn both a keyboard instrument AND a melody instrument. I think you'd be at an advantage with that approach were you ever to want to apply for a college of music.

I've said all that and never followed any of that advice myself. I dropped music at school (the teacher was a bully) and ended up as a completely untutored harmonica player. Sheesh. But I've had a lot of fun with that. And therein lies another consideration...