or later. Version 3.6.4 is considered a legacy update suitable for older macOS environments. between this version and the latest MainStage 4.0 MainStage release notes - Apple Support (AE)

Once you mount the and drag the app into your Applications folder, launch it. The first boot will ask you to download the "Essential Sounds" library (approx. 5GB). This includes the Studio Horns, Vintage B3 organ, and the massive Alchemy synth library.

Before double-clicking, check the file size. A legitimate MainStage 3.6.4 DMG is approximately . If the file is 2 MB, it’s a fake.