Like where I could buy my songs drm-free and keep them forever.
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.
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
Bandcamp and Qobuz
I usually get mine from either Bandcamp or Amazon. No DRM from either when downloading, though buying music from Amazon gets difficult if you have an Amazon music subscription.
Time to put on the hat and that eye patch!