Beyond GarageBand
When you feel ready to move beyond GarageBand - for example you want to edit and print notation, export midi files. record more tracks simultaneously at higher resolution, etc. - then Apple's Logic is for you. It comes in two flavors, Logic Express and Logic Pro. Both have full GarageBand integration, so you can import GarageBand projects and take them to the next level.
Logic Express lets you produce a convincing demo of your band, create a remix of your favorite track or score QuickTime movies. This affordable virtual studio integrates a rich feature set for both music and audio production in one application. In addition to Apple Loops you'll find a wide variety of software instruments. These provide, for example, faithful emulations of vintage keyboard classics as well as synthetic sounds, ranging from digital to virtual analog. Composers and music theory teachers will also appreciate the full-featured score editor.
Take a tour...
Logic Pro 7 is the complete professional solution for music creation and audio production. It combines an award-winning sequencing and audio workstation application with a comprehensive set of software instruments and plug-ins, state-of-the-art loop composition tools and the ability to utilize networked computers for additional processing power. With Logic Pro 7, you can take on any task in the pro audio workflow.
Take a tour...
For some good Logic Tutorials, see Pete Thomas' site.