Missing or unavailable music is almost always a decision by the artist/label to withhold the content from Spotify. Sometimes it's temporarily unavailable while they sort out legal issues or correct metadata, in which case it'll be back up as soon as they resubmit it to Spotify. If you're looking for some more information, it might be a good idea to contact the artist or label directly and ask why the music isn't on Spotify. You might also be interested in supporting this idea, which suggests a simpler method for requesting albums missing from Spotify. For more information on missing content, please check out this support article.
Something I tend to do when I can't find the music I'm looking for is adding them as a Local File. Click the link to find out more information about how to upload your own files to Spotify 🙂
These are the types of file types currently supported by Spotify:
.m4p (unless it contains video)
.mp4(if QuickTime is installed on your computer)
Let me know how it goes!
Thanks for reading! If this worked for you, please mark this as the solution, this way others will be able to find the answers to their problems in the future! 🙂