If I mutter this quietly, maybe no one will complain to you.
We have a 2 CD set of The Tolkien Ensemble and hope to get their latest At Dawn in Rivendell
which was just released in the US last month. They are excellent. The Danish singers are very good and their slightly accented English makes the lyrics more rounded and fitting. I have not heard Glass Hammer, though I've heard good things about them. Thanks for the recommendation. So little time, so much music...
On "Sound and Spirit" in November was a program with LotR as the theme. The host played a couple songs by a Dutch group, The Hobbitons. I've visited their website and plan to send them $20 for their CD.
There is also symphonic music based on Tolkien.