
As far as I can tell, everything up to Hot Space came out on 8-track. Maybe that doesn't quite qualify as "unusual", since 8-tracks were a big deal for a good period of time, but I find those releases interesting because the songs are often in a different order, to make the "tracks" roughly even in length. Like, speaking of Hot Space, Las Palabras De Amor is after Dancer, and it's split into two parts at that!
The one that really surprises me is that Greatest Hits and The Game were released (by Elektra in the US, anyway) on reel-to-reel. I had thought that pre-recorded music on reel-to-reel tape was already a thing of the past by then, but I guess it kept hanging on until the mid-'80s, who knew?
The only other one I found was Minidisc, which GH, GH II, and GH III were all released on. Makes sense, I guess, because II and III, at least, were released when MiniDisc was kind of a thing, or right around the time. Maybe it was more successful in the UK and Europe than the US, I dunno, but I think I only ever knew ONE person that had them, and I believe it was just used as a recorder in that case.
Anyone know of any thing else like that? I know Digital Compact Cassette was around at the same time as MiniDisc, but I can't find any Queen stuff on those, there just wasn't a lot of prerecorded music released in that format anyway. Of course, it's pretty much gotten to the point now where ALL physical music formats are obsolete, or getting that way, hasn't it?