Spotify - SSD or HDD

You could move it to your HDD but you can however change how much the Data file fills by editing the file named "pref" in the Roaming files

C:\Users\*USERNAME*\AppData\Roaming\Spotify\prefs

But FIRST,
Close Spotify
go to:

C:\Users\*USERNAME*\AppData\Local\Spotify\Data

and delete all files inside of it. This is that stored data.
THEN, go to:

C:\Users\*USERNAME*\AppData\Roaming\Spotify\prefs

Edit it with any program, even wordpad (don't use notepad) and enter this option in at the bottom of the list:

storage.size=*desired amount of megabytes*

Here's mine set for just over 1 gig:

storage.size=1280

Save the file, and then you can reopen Spotify. It will however need to store some kind of cache. But 1gb can be a lot for just music. And the IO can be a lot of extra IO for the SSD. Also epic privacy browser has a youtube download plugin built into the browser for free and I switched to that and have all my favorite albums and playlists saved to my Database.