This is the definitive final release of the "modern" GarageBand (v10) that supports OS X 10.11.
An older "classic" version that many users prefer for its podcasting features. It is confirmed to work well on El Capitan, though it is no longer officially sold. How to Download GarageBand on El Capitan garageband el capitan
How can I install Garageband on El Capitan - Apple Community This is the definitive final release of the