I like tracker programs like Modplug. It's better than Cakewalk no matter what some people may say. Oh yeah, and Modplug is free. You don't have to pay anything. It's freeware.
When you start using it you're going to be confused. There are up to 64 different channels which pretty much solves your problem. All you do is get a few samples. If you want some background drums you can either use individual samples of drum beats and play the drums with your keyboard or you can create a drumbeat yourself and make it loop.
After that you can do the same process with bass. With your guitar work you can either make loops of your playing (it saves space) or you can go crazy and do a 10 minute solo. You can just put it in there as one of the samples.
Go download the program over at
http://www.modplug.comHere's how to begin using it:
After you create a new file, File ----> New ----> IT, hit the Pattern tab that you see. Modplug's music interface takes a little while to figure out. Just remember it's kind of like Microsoft Excel. There are columns that go downward. There is a long line that goes all the way across the rows and as it goes down it plays your musical notes. Musical notes are represented by a letter and a number like C-4 . That's a C note that's in the 4th octave. Ok, at the top of a row double click in one of the white boxes with dots in it and select the C-4 note. Close that little box and goto the samples tab. Put any wav file that's on your computer in it. Double click on the C-4 note you just made. Hit the dropdown box that is beside Instrument. Select that wav file. qwertyuiop[]\ <---all of those buttons that this arrow is pointing to are your musical notes. You can play them like a piano. Click on your C-4 note once. Press the play button up there near the top of the window and go crazy. Start playing your keyboard like a piano.
(BTW, there's a whole lot more to it than that. The loops you can make with your samples, etc. It seems kind of complicated but once you get the hang of it you won't use anything else except other programs to record your loops and samples to use with Modplug).