Ah! Ideal with questions I have this thread, so not particularly hi-jacking, since it's highly related

Hopefuly I'm still not an evil begger to post in it though.
I composed my first piano solo piece recently (infact I made revisions yet again today!), except some people have asked me: "What kinda style is it?" or what kinda genre...
What can I say? I mean... certainly not Jazz, blues or soul... it's just a piece :/ If anything it's classical I guess, but I'm not sure what defines it into the classical genre.
Also, I'm not sure what IT IS if it's classical. It was supposed to be a Piano Sonata, it has 4/4 Beat so no Waltz or anything. It lasts 4 minutes and is just a single movement (Prok 3rd is a single movement too), but I thought it might be too short to be a sonata O_o Not a prelude or Polonaise me thinks... Hybrid form? lol
Oh, and I also tried to implement structure... of some sort, the theme varies throughout but eventually returns at the end (and in the middle somewhere), and also speeds up and slows down with FF to PP etc. so... it isn't crazy throughout!
what do you have to know to compose a music??
For me, the complete amateur with the simple if not wrong answer (but got me somewhere):
Know how to build a scale and simple chord structures; C Major Chord + Inversions goes a long way, then I just transposed the odd key when it seemed neccesary, until I got what I wanted ^_^ My piece is technically pretty cheap, but it's a first try

It certainly is fun composing, if you have the concentration which I don't ~_~ Tried composing now, instead I ended up playing old pieces in my repertoire O_o