I was just trying to listen to an album I bought last year, and several of the tracks weren’t playing, and on checking the Finder, I noted that those tracks were Apple Music placeholders rather than the m4a files I expected. I tried removing the downloads, and re-downloading, but that didn’t help, so I decided to go for the… intense… option and deleted the album, on the assumption that I could just re-download it.

I could, but if you delete an album from your library, Apple Music very helpful makes it impossible to find in your purchased music. The only way to get back to the album listing is, with Apple Music open:

• In the menu bar, select Account > Account Settings.
• In the modal that appears, scroll down to the Hidden Items section. One item should read “Deleted Purchases: Unhide any hidden, redownloadable Purchases”¹ with a link labeled “Manage”. Click that.
• Now you will see a list of Hidden Purchases that you can choose to re-download.

This is a stupid design. But at least next time I do this, I’ll have this note handy to remember what to do to fix it.