I think good music makes a good game great so I want to get into composing music for videogames.I have a low-end keyboard with 100s of sounds on it but it's very hard to make complete tracks with. I have less than $100 to spend on a music program for the computer and after looking around I found Sequel 2. I like how it has many loops & sounds built into it. I'm wondering if and how you connect the keyboard I have (it has SD & USB slots) to Sequel 2. (Also, is this a good program in the first place? Any other recommendations?)

What make and model is the keyboard? As for connecting it, it may not be possible, it really depends on the USB ports intended use.

This is the keyboard here:

http://www.axemusic.com/product.asp?P_ID=19544&strPageHistory=search&strKeywords=Casio,keyboards&numPageStartPosition=1&strSearchCriteria=all&PT_ID=all

Sorry, double post

Honestly...this is what I prefer to use for most music projects.
http://cgi.ebay.com/SONY-MINI-PLAYSTATION-with-LCD-SCREEN_W0QQitemZ260430895966QQcmdZViewItemQQptZVideo_Games?hash=item3ca2e41b5e&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1205|240%3A1318|301%3A1|293%3A1|294%3A50

http://cgi.ebay.com/MTV-MUSIC-GENERATOR-PLAYSTATION-1-2-3-COMPLETE-PS1-RARE_W0QQitemZ130308899361QQcmdZViewItemQQptZVideo_Games_Games?hash=item1e57040221&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1205|240%3A1318|301%3A1|293%3A1|294%3A50

Small, compact, portable, and for most music formats, it's good enough.
Some of the sample sound qualities are a bit dated, but if you want to know how it sounds, here's two of my pieces of work for example:
This one is purely the machine.
http://www.garageband.com/mp3/Pencil_Dust-Nightmare.mp3?|pe1|S8LTM0LdsaSgZFC1Ymw

This one is the machine mixed with me playing a guitar over the top.
http://www.garageband.com/mp3/Pencil_Dust-Theos.mp3?|pe1|S8LTM0LdsaSuZlK1Zg

Do you have an audio interface (sound card) with midi in?

If so you can use the keyboard as a controller with midi, doesn't matter if the USB mode will be compatible or not.