Prerecorded media overview
GarageBand comes with a large collection of prerecorded loops, offering a great starting point for many of your projects. You can start composing a song by dragging Apple Loops from the Loop Browser to the Tracks area. You can also use the Media Browser to import songs, movies, and a variety of other prerecorded media into your project. Combining existing loops and other media files provides a quick method for laying down project foundations.