[mogery]

Spotify DRM is basically security through obscurity. It's just AES-128-CTR over a plain old OGG file. The tricky part is figuring out the extremely odd protocol you have to request audio keys and track data through. That's all.

[seabrookmx]

Sounds similar to many encrypted HLS streams you see on the internet.

If you're savvy enough to watch the network tab in the browser devtools, you can grab the key and easily decrypt and assemble the chunks. You can even find reference implementations on github (hls.js for instance).