Like where I could buy my songs drm-free and keep them forever.
Time to put on the hat and that eye patch!
Bandcamp.
FWIW songs on iTunes are drm free.
Also if the band has a website.
Bandcamp allows to buy drm-free music. You can just have the files on your desktop and play them, or use an app like Jupii (available as a Flatpak) to play your Bandcamp library. I havnt tested the app myself yet tho.
Bandcamp and Qobuz
I use Qobuz. They have options for high quality flac downloads. Their download app isn’t native Linux, but you can download one by one from the web.
There is a handy Python app for downloading from qobuz, although I think it might be more of a webrip rather than straight download