I've looked up sound conversioin programs, and though I've never gotten around to downloading any, I see tons of various programs(freeware) that boast that they can do those conversions...
I use Yahoo.com search

I like it more than anything else...*hugs the Yahoo
! search*
Midi to Wave sounds possible. Wav to Midi sounds like it would need decent sound recognition, using my understanding of Midi. What I've
been told, is that Midi is a bunch of notes that are played by your computer. Like a text document compared to a .jpg image(.wav comparison). Is this correct?
Sound composing...
Err... all I know of is a program which allows you to make Midis. It lets you place notes, has 8 tracks, plenty of instruments, tempo, and a few other things. I like it more than most I've seen, 'cause you place little dots in the places instead of notes, 'cause I've never learned note-language. It's easy to use, and even
I(!!! GASP) have made some not-so-horrible-sounding things with it. They still suck badly though, and I can't seem to get a good boss-music-sound going with it... \: Oh well it's still cool. It's not free, but you
can get a trial version. It hasn't stopped working for me
It's called Midi Maker. Simply Midi Maker. I'll try to find it if someone says they want it.