I relate to you because there are missing albums from Overkill, Motorhead, W.A.S.P., Tankard, Accept, Dio as well because I want to have Angry Machines, Magica, Killing The Dragons, and Master Of The Moon on there.
That answers it for some music. But my question is why are some albums up, I listen to them, add them to playlist, add them to my Songs... but then they are all of a sudden no longer available? For example, Brandtson - Hello, Control was on for a few month and then was gone. I can still find the album through a web search which will open the album in my app on my laptop, but the entire thing is greyed our despite having checkmarks on some of the songs confirming I had added them to my Songs. What gives?
From what I can gather Spotify will need to pay the artists/companies which makes sense. Some people will want more royalties than others on certain songs which would answer why some songs are missing or some albums (different producer, writer and so on). Spotify probably only pay monthly rather than annually for albums and songs. This is a pure guess and I could be wrong. I'm more miffed about the limit of songs you can have in your library and that's not downloaded. And from what I can see, albums saved and downloaded count as double.
It’s not Spotify’s call. There are bands, labels, etc that have to make the decision to have albums on Spotify. For example, if a band was on an indie label for all but 1 of their records, then they may have every album for that artist on Spotify except the one that was on a Major Label if the Major did not agree to the terms required to have that album on Spotify.
For example, Maynard of Tool has explicitly said he does not allow Tool songs on streaming apps because he believes Tool albums are meant to be listened from start to finish rather than arbitrarily. However, he has no issue with A Perfect Circle’s full discography being available.