You can also change the Theater View Caption under Options, Theater View, Advanced.
Here's an example of what I use today. This example is from back in the day when Media Sub Type was not present, or did I just change it to reflect the new changes? I'm not sure. Anyway... The Consert and Standup values are not a Media Sub Type. But as I'm at work now, I have no good tools of removing those without messing up the expression. It does not hurt to have them there in any case. It will just not be used.
If(IsEqual([Media Type], Audio),[Name] - [Artist] - /([Album]/) // Rating: [Rating],If(IsEqual([Media Sub Type], TV Show),If(IsEmpty([Name]),S[Season]E[Episode]/ (NP:[Number Plays]/),S[Season]E[Episode]/ (NP:[Number Plays]/) - [Name]),If(IsEqual([Media Sub Type], Music Video),If(IsEmpty([Artists]),[Artist] - [Name],[Artists] - [Name]),If(IsEqual([Media Sub Type], Conserts),[Artist] - [Name],If(IsEqual([Media Sub Type], Standup),If(IsEmpty([Season]),[Name]/ (NP:[Number Plays]/),[Name] - S[Season]E[Episode]/ (NP:[Number Plays]/)),[Name])))))
This gives you a much better caption for TV Shows and Music Videos imo. Movies are not mentioned, and will therefor use the standard [Name] expression. This reminds me again what a hell it is to edit and create such Expressions. I pray for a better expression manager in MC, or separation of caption expressions for different media types.