Themes removed from larger Public Domain works

[Amelia.pd]

If themes or movements are taken by publishers from orchestral works that are in the public domain can they legally be protected by copyright if they haven't been arranged?

Many different publishers have removed Schubert's Overture Rosamunde

[Carolus]

In a word, no. In order to make a valid copyright claim, the claimant would have to alter or modify the theme in an original manner (not merely transposing it to a different key), provide a new harmonization or orchestration. The theme itself in its original form is public domain.