Regarding the issue of the composer type tags / 关于“曲作者”类标签的问题
曲子作者作为标签的时候，应该将其归类到“媒体”还是“素材”？
When the composer is used as a tag, should it be classified under "Media" or "Source"?
t180.1: In my opinion, tags for musical artists should be avoided and seldomly used. Create song attributes for them instead like 石川淳. Tags for musical artist should only be made if they are being sampled (therefore classified as a source, ex: Kanye West) or if the directly contributed to a work (classified as a creator; ex. NOMA). I think that tags for musicians should not be marked as media.
Before the edit, you asked if there was a way to denote that a creator contributed to the music of the work. This already exists as the "Music" role. Again, I think this should only be marked if the musician directly contributed to the work and not just because the musician's song was used.