Another nod to Guitar Tracks Pro 4. You can hear it in use here on this track I made:

http://ewguitar.com/2011/07/15/feelin-it-by-earle-wood/

It has virtual bass and drum rigs as well as a strings section and a virtual piano. The sounds aren't perfect, but more than good enough to get started.

Earle Wood
www.ewguitar.com