Quite impressed.
wow, from four notes eh...
Heh, I have a song like that, from four notes played at the same time actually, however I know how you feel, sometimes I hear a few notes at random, and then I expand on it LIKE CRAZY. Most of the tunes never come to life, but heh, i'm glad you were able to.
It's a great piece, though I feel you should use a compresser, it distorts in some places, gets a bit too loud.
I am glad you did not use any flangers or use any percussional work here (though maybe a simple snare roll might sound neat), it keeps the song intact.
Good job IamMark
4/5 from me, keep them coming ^^.