Hymnary.org has a bunch of information about hymns and hymn authors, showing what hymnals they appeared in (along with scans of hymnals), what tunes they use, and what hymns authors wrote. I was using them as a reference when working on some works on MB last night so thought I'd suggest adding 3 of their types of pages as external link relationships to make them easily linkable.

First, texts https://hymnary.org/text/when_peace_like_a_river_attendeth_my_way and second, tunes https://hymnary.org/tune/ville_du_havre_bliss 

Both of those could be linked to works, I think it'd make most sense if you linked both to a hymn work with the caption on MB specifying one is a text and the other is the tune.

Third would be persons https://hymnary.org/person/Bliss_Philip . This type would be linkable to artists.

For more information about Hymnary you can read here https://hymnary.org/about