I ran the feed through a validator and it passed. It is just empty!
I think you used pages to add your songs instead of posts. You won’t get RSS feeds from pages.
If I’m right about this then you might start converting your pages to posts and further use the categories to ‘drill down’ and help index your songs.
You can further ‘drill down’ by artist, key, style, holiday… etc.
Imagine being able to go to your present index table (which could be a page still) and clicking on ‘Abie Rotenberg’ and getting a whole list of songs by Abie Rotenberg in a category that would then have its own category ‘feed’ if you wanted to add a RSS button or link to that table. Or sub tables even.
Imagine a visitor who needs a song in a certain key being able to find it and others like it by clicking the specific key category link.
You could add instrument and/or vocal categories. Think guitar, mandolin, choral, soloist, piano, etc.
Doing the above would help the search engines find and further index your content.
You don’t need to do this work all at once either.
And here’s more info about using categories and tags. https://www.wpbeginner.com/beginners-guide/categories-vs-tags-seo-best-practices-which-one-is-better/
