A song from a musical or a film does not say which show or film it comes from #707

The problem

A song from a musical or a film does not say which show or film it comes from.

"Popular" is from Wicked. "This Is Me" is from The Greatest Showman. "The Phantom of the Opera" is from the musical of the same name. Soundtracks and cast recordings are a large share of what singers practise with, and for these songs the show is the thing people know them by.

At best, the track shows the performer: Kristin Chenoweth, Keala Settle, Michael Crawford and Sarah Brightman. That is accurate and it is the wrong headline. Someone preparing an audition piece thinks "the Wicked song", not "the Kristin Chenoweth song".

Why it is not just reading the album name

The show is usually sitting in the album or the title: "Wicked (Original Broadway Cast Recording)", "The Greatest Showman: Original Motion Picture Soundtrack", 'Popular (From "Wicked")'. Pulling a name out of that text is the easy half.

The hard half is knowing the name really is a show. "Wicked" is also a novel, several bands and more than one film. Taking the text at face value would happily present a same-named band or book as the source, and the result looks authoritative while being wrong.

Constraints for a fix

• The show is found from the album or title, including the usual "Original Broadway Cast Recording", "Original Motion Picture Soundtrack" and 'From "..."' shapes.
• It has to be confirmed as a musical or a film on Wikidata before it is shown. A same-named band, novel or album is not a match.
• The performer still matters. The show becomes the headline and the performer comes second. Neither disappears.
• Ordinary songs are untouched. A track that is not from a show looks exactly as it does now.

Being worked on in the feat/song-identification branch.