songs from TV shows (as in sung by the cast in a musical episode or otherwise, not a guest musician on the show, also only fiction shows so nothing from talk shows or the like), songs from movies in the same vein as the ones from TV shows.
Judy Garland got really fat and Hawaiian.
I couldn't have Bowie in Extras with an original song because he was a "guest star" but somebody can nom a cover version of a song from a movie by somebody that was never in the movie at all. Just saying, cover versions in the theme post would have opened up a lot of possibilities.