(it's not really a musical anyways)

But I think "charming" is a good word.

The biggest problem I had with it is that it falls into the trap of stopping the film so somebody/ies can sing for five minutes without a) advancing the plot (as a musical would) or b) having the musical performance itself - in this case, not the music, but the way it was staged/filmed - be strong enough to stand on its own two (as a drama film about musicians is forced to do).