This post contains indirect potential spoilers for Unnatural Causes, a book which is still in the editing process and thus some ways from submission, much less publication ... which makes the odds of remembering an unspecified song reference, out of context, years later, vanishingly tiny.
Still ... you have been warned.
I love a "Yes, but" ending in my stories, and my novels are no exception, so most of them are open to a sequel, even if I haven't specifically planned or even intended to write one. I have some half-formed thoughts for a sequel to Unnatural Causes, and I know that this would be a fitting song to represent the romance storyline:
Near To You - A Fine Frenzy