Of course i already realised that many amazing songs for example More from Usher don't exist on Spotify. (Whyever... maybe sb can say me why?) And now there are many songs, which are not the original, where some time before the Original existed. For example Run this town of Kanye West... or Miss California od Dante Thomas. I mean that are no noname songs... they are widespread and i think im not the obline one who wants to listen to that songs with Spotify Premium , like i did some weeks before...
The reason is that the artist or their music label has likely decided to remove it from Spotify.
The availability of music on Spotify is up to the artist and their music label.
Spotify wants all the world's music, and they're working hard on making this happen for you. However sometimes agreements can't be reached with the artist or label or a change may happen in music ownership. Sometimes the music is only available in certain countries, while access is blocked to others. Sometimes the album or song will be unavailable temporary, and come back again later.
The songs/albums will still be shown in your playlists so you can keep track of them. Make sure to go in settings and check for the setting that shows unavailable songs.