<p>It could mean either- though a song that has been IN a show would virtually always qualify. (there are some shows like Rock of Ages that are made of covers of songs by Journey etc- that would be less appropriate) There are also songs that are “standards” which would qualify as well, even if they were never in a show- or aren’t particularly identified with a show. Think “Night and Day” or “Come Fly with Me”. (yes, both of those have been in shows- but I don’t think it’s the main way someone would identify them)</p>