Copyright is convoluted and the courts are not consistent. In music some entity owns the copyright to use of the piece of music. A separate arrangement of the same piece (say, in a piano folio like my daughter has -- where I was just checking for who holds the copyrights for the various themes) can have its own copyright. Then there is the copyright on the recording. Plus LaLaLand would have the rights of its specific arrangement and packaging. Yikes.