If your Mac cannot run the current version, you can often download a compatible 10.4 release if you have previously "purchased" it: Garageband 10.4.9 - Apple Communities
Typically, GarageBand is delivered as an invisible update via the Mac App Store. Searching for a standalone .dmg (Disk Image) installer usually implies one of three scenarios: garageband 10.4 dmg
GarageBand 10.4 represents a significant milestone in Apple’s journey to democratize music production. Distributed primarily through the Mac App Store, though often discussed in the context of files for archival or manual installation purposes, this version solidified the software's transition from a hobbyist tool into a "Logic Pro Lite" powerhouse. The Evolution of the Digital Audio Workstation If your Mac cannot run the current version,
If you find GarageBand’s features limiting for professional work—such as its limited hardware support for high-end interfaces—you can easily transition your project to a more advanced Digital Audio Workstation (DAW). The Evolution of the Digital Audio Workstation If
If you have a friend with GarageBand 10.4 installed, you can copy the .app file via AirDrop or an external drive. Otherwise, clear 15GB of space on your drive and hit "Get" on the App Store—it’s free, and it comes without the risk of malware.