Please Help A Newbie Options

[slimjimmed]

I have a new G5 and a usb midi keyboard i recieved as a gift. Since I am new to the field of computer music, i need some basic advice. I want to know what kind of software i need to buy if i want to have a collection of musical voices to play with my keyboard. What i am really looking for is weird tribal and spacy music that i could use to score my short films. Additionally, it would be cool to have a nice piano and organs.
I'm looking for cheap($100-ish or below) software. I don't know if it would be a major contradiction to spend so little money and get quality sounds since i am ignorant to using my computer for recording?
I don't know if i need Vst's, synths, samples, etc... I am frickin' lost. I was looking at Sonic Refills and ProSessions, and they seemed to be the type of sounds i was digging, but i don't know if i'd have tgo shell out for some proprietary software that costs$$ in order for them to work with my keyboard. Thanks for your patience.

[nate d]

Propellerhead Reason is the software you're looking for. It has tons of weird sounds along with pianos, organs, drum machines, effects.....everything you'd ever be looking for! It's out of your price range ($350 US), but I couldn't recommend a better piece of software. I bought version 2 on eBay for $200 and Propellerhead gave me a free upgrade.

The Sonic ReFills you mentioned are actually used with Reason, so they wouldn't do you any good by themselves.