If you're open to physical media you can probably request it through your library, or similarly buy the dvd from ebay or something.

And for some non-geoblocked music, if you want to actually purchase the song as MP3, there's no way unless you have a Mac or Windows PC to install iTunes (too bad for Linux users).

https://uk.7digital.com/ has a lot of songs available in MP3 format, but not as many as on iTunes.