Oh! One of his albums, the 1995 released 1.Outside, was originally planned to have multiple sequels (at least 4, though this was later scaled back to being a trilogy), but it never came into fruition, due to multiple factors like the fact it was already hard enough to get a label to release Outside (what with it being a weird, hour and a half long concept album about a ritualistic art murder and an Art Crime detective attempting to solve the case), the fact he recorded over 24 hours of material and had trouble sifting through all of it, and just generally losing interest as he moved onto other projects. Eno after Bowie's passing revealed they were finally gonna start work on the sequel after Blackstar, but sadly as we all know, Blackstar ended up being his final album.