Man, you can improv the hell out of jazz
Hey, what up bud? I'm back, and you've changed your name :)
This is very smooth, I like the choice of notes are your improv, you clearly have practiced a lot of different things on your own time. Unlike lots of artists around here :).
My only gripe is, this Band in a Box thing. Sure, you say you only play reed instruments (right?), but you should seriously consider learning to compose your own music entirely. You can definitely do it, based on your music theory knowledge. Just a backbeat on the drums, some basic guitar chords with 7s and 9s in the back, some strings, and even try using more than one reed instrument in the song! Like, you could play an alto sax part, and harmonize a clarinet part with it.
You can find free software on the internet that lets you make any instrument you want with a cheap electric keyboard, via an interface called MIDI, if you want to look into it. I'd recommend it!
Aside from those few off-topic paragraphs, all I can really review you about right now is your improvisation, not really the song, so your reviews from people are going to be short. Again, look into writing music! You might really like it.
See you around!