An exception is for scientific or critical editions of works in the public domain. Per article 70 of the German copyright law, editions as the result of scholarly or scientific analysis have a copyright length of 25 years. Therefore, the editor of an urtext score of an opera by Beethoven would only receive 25 years of protection, but the arrangement of the full orchestral part for piano would receive a full 70 year protection - timed from the publication of the piano arrangement and not the death of the editor.