Also, in part, because I really wanted to like this book, because I really respect the recommender. Unfortunately, I didn't.
Book is The Soprano Sorceress, by L.E. Modesitt, Jr. Recommender is accioayla. Sorry, dear. Started out sort of on a bad foot with me, when the heroine gets whisked off from her singing engagement at the Dean's House to Jenny's cottage, in another world, another time. And basically the second thing she says is "Where is Jenny's cottage? And when?" No real sense of disbelief, no sense of "WTF just happened to me!?!?!?" The character just doesn't seem real to me, from the very beginning. Made it really hard to get into this one.
The second problem I have is that while the book does have interesting elements - the song/magick structure, the modern woman whisked into medieval world to save it - the elements kept reminding me of other books I've read that had similar elements, that I liked better. Spellsinger, by Alan Dean Foster, was funnier. The Fionavar Tapestry by Guy Gavriel Kay has much better character development and treatment of the modern characters and their sacrifices to save the medieval world they find themselves in. Gossamer Axe, by Gael Baudino, I liked better for the music/magick dynamic.
So, this one just didn't do it for me. Still, a good book - and it certainly reminded me of a bunch of books I want to reread and recommend myself.