Nightingale's Lament (Nightside, Book 3) 1st edition

In the Nightside, the hidden heart of London where it's always 3 AM, Detective John Taylor must find an elusive singer known as The Nightingale. Her silken voice has inexplicably lured many a fan to suicide--and Taylor is determined to stop her, before the whole neighborhood falls under her trance. But to catch the swift-winged Nightingale, he'll have to hear the deadly music--and survive.