Starting last Saturday, all 216 Guitar Center stores in the U.S. have begun offering a four-week, rotating series of free seminars showing customers how to use Garageband and a Mac to record their own music, called "Recording Made Easy." The classes take place on Saturdays from 10 a.m., with this week's focus being on virtual instruments and loops. Future sessions will include topics such as effects, mixing and publishing, and then the series will start again with a discussion of signal flow and microphone techniques, AppleInsider reports.