Classical / film score: how does that work?

[BlackJack]

It’s the composer, not the artist, that makes a composition count as ‘classical’. See also here:

Have you ever wondered what the 'Only Classical' switch is good for?

The Compositions Browser You can choose to only display Classical compositions by setting the slider toggle at the top right of the display to “on”. [grafik] So what makes something count as a classical composition?

Why soundtrack, musical and the such count as classical? I guess we have to ask TiVo/Rovi (allmusic.com) why.