While Apple has moved on to version 3.7 and 4.0 (with features like surround sound support and improved accessibility), the remains a critical tool for working musicians who prioritize reliability over bleeding-edge features.
Since you should only get MainStage from the Mac App Store, the process is straightforward: MainStage-3.6.4.dmg
Appendix B — Minimal troubleshooting commands and steps While Apple has moved on to version 3
Understanding MainStage's version history provides crucial context for why you might need the 3.6.4 DMG. Apple frequently updates the app, and each version has specific macOS requirements. MainStage-3.6.4.dmg