The Last Days by Scott Westerfeld

Moz and Zahler have been playing guitar together for six years.  One crazy, stifling night in New York City, a woman throws her stratocaster guitar-- and all her other posessions-- out her apartment window.  Moz grabs for the guitar at the same time as Pearl, a gorgeous and-- he soon finds out-- incredibly musically talented teenager.  Moz, Zahler and Pearl form a new band while the rest of the world seems to be falling apart around them.  The subways seem to be alive, there are beasties under the city, and the rats and other spirits have taken over dark alleys.  The novel is told in the first person of each of the new band members on rotating chapters.  Fast-paced, intense, and dark.  A good companion to other high-school vampire stories that were raging in the mid-to late 2000s.