I put all Zappa albums into one playlist, sorted by release date. From Freak Out!, debut of the Mothers of Invention, to the posthumous release Mystery Disc. You can subscribe to it now and (hopefully) the tracks will be available as soon as the last license issues are sorted out. If you are a premium user, you can set the playlist, or some tracks, as available offline, so you will know when the playlist/tracks become available (to download) without checking everyday.
Get this collection in one Spotify playlist: Frank Zappa: Chronological Discography (available soon) (917 tracks, 56 albums). Ctrl (CMD) + G to browse in album view. To see the full list you need to uncheck "Hide unplayable tracks" in Spotify preferences first.
I discovered Zappa through Wong Kar-wai's 1997 film Happy Together (the scene accompanied by Chunga's Revenge is one of the highlights), and adored the few albums I bought afterwards. Thanks to the Zappa Family Trust, and content team at Spotify, now I look forward to discover more from this monumental catalog on the best streaming service in the world.
P.S. For interpretations of Zappa's works by modern ensembles and orchestras, check out my previous playlist: Zappa as Composer. For 18th century Italian composer Francesco Zappa (apparently not related to Frank, though the latter claimed so), here's a new release of his six symphonies.
Update: All albums are now available on Spotify UK and some other European countries.