Unfortunately, for now, there's a limited amount of artist lessons. I'm hoping the selection will grow over time, since it is one of my favorite features of the Learn to Play function. The process of selecting artist lessons in GarageBand and then being switched to a Web browser to pay for them via the Apple Store Web site and then going back to GarageBand to download them is a little confusing. It would be better if the entire process were built directly into GarageBand, but this is more a minor irritation than a real problem.
Of course the big question is, can you really learn an instrument this way? Overall, you can at least get the basics -- so long as you put in the time and practice. I certainly learned more in the first few guitar lessons than I did in my attempt to teach myself to play several years ago. You do have to really commit to practicing and listening to your own progress, however, and it helps to be good at self-directed learning. That's an advantage to working with an actual instructor that can't quite be replaced by GarageBand -- you don't get personalized recommendations for lessons or practice, nor do you have someone experienced watching you and telling you if you're getting into any bad habits. So, yes you can learn to play with GarageBand, but be aware of the limitations inherent in the approach and realize that virtual instruction will probably only take you so far.
Beyond Learn to Play, GarageBand features a handful of additional updates. One is an improved new project interface that allows you to choose between the varying features of Garage Band at start-up. Specialized options are available for new projects, Learn to Play, the Lesson Store (where basic and artist lessons are downloaded), Magic Garage Band, iPhone ringtone creation and a list of recent projects. Even within new projects, the interface is more granular about the types of available projects, which offer predesigned settings and tracks aimed at specific types of recording or editing.
Magic GarageBand has been enhanced, too, giving you more control over which instruments are used when auto-generating a song. The interface also now allows you to define an instrument and record yourself jamming along with GarageBand's creations without moving into the primary editing screen. This is a fun feature that makes getting your feet wet with GarageBand a little less intimidating.
For electric guitar players, GarageBand offers a selection of virtual amps and stomp box effects. Each one is patterned after the controls of actual rigs and allows you customize your sound in the same way you would if you were using physical gear. Thirty preset rigs are included, but you can further customize the combination of virtual hardware. The result is a diversity of creative power that most amateur musicians wouldn't be able to carry off with real equipment because of the cost. It also offers a playing and recording experience that more accurately mirrors what it's like to use real equipment instead of a computer. Obviously, this feature applies to a more limited set of users than other GarageBand features do. But Apple did a good enough job with the interface that it's worth noting for electric guitar aficionados.