Garageband for Mac OS Mojave

I can confirm what Keith wrote.

I can download both GarageBand 6.0.5 and GarageBand 10 by clicking the download arrow to the right of GarageBand in the list of my previous purchases. You may have to try several times. Don't give up. Make sure you have installed all updates for Mojave.

• Open the AppStore.
• Click your name at the left bottom corner in the sidebar to see your Purchases.
• 
• Find GarageBand 10 and click the download arrow. You will see a warning that you need an older version like this.
• 

Click download.

If you do not see GarageBand in the previous purchases, check your account for hidden purchases.

Unless it shows up in the purchases tab of the app store, it is no longer available.

Did you download the latest for another computer?

Not the "Purchase" tab, but the "purchases" tab. Click your name at the bottom of the app store page.

I just checked mine last night, and my purchases tab has all the Garagebands that I have downloaded, even before Big Sur.

Great 😀