That sounds pretty darn good for fooling around as you call it. Actually the sonic level here makes you think you are singing with a tight band. I take it you are liking your new 900 over the 3000? It seems to me a major difference in sound from your older keyboards, even my old 3000
Your singing sounded good also, and you've got a great technique for recording, mixing etc.
That S900 sure sounds to me like the biggest dang bang for the buck I've heard.
Scott