Hey now.... wouldn't that be a great schtick for the Quadio Program? Each boxed set offer FOUR Quad albums, like the Doobies set.
Joni had two released and supposedly one unreleased. If they could dig up another unreleased, and baby makes four.... that would be cool.
If they could kick Don Henley in the teeth and do the same with Eagles Debut, Desperado, Border and Nights.... there's four. (We already have Hotel).
There's four Johnny Winters'.... three released, and one not. (Not sure who controls his catalog anymore).
Easily do four Edgar Winters' between the released and not....
Mac Davis?
Loggins & Messina? (Self-titled, Full Sail, Native Sons, maybe an unreleased fourth title?)
Paul Simon (Bridge, Self, Rhymin' and Still Crazy...)
Jim Croce .... if only. I know, I'm dreaming on that one.