I have seen the sound making-of mentioning the location sound procedure in the recent feature film "Les Miserables".
They have been capturing the vocals of all musical songs live on set and mixed them up with the orchestra sing along in the post. This is an interesting way of doing it, since the usual approach would be to record the song in the studio and shoot the film similar to a music video with a playback.
My question is:
I am wondering to what the actors were singing to on set. They would need a sort of playback or not? Playing the playback on set through speakers would mess up the vocal sound. An other way would be in ears...are there some invisible models? Or are they singing to a sub-frequent click track, that can be filtered in the post.
Do you have other ideas how the actors where able to listen to the sing alongs.