Children of the Night: A Diana Tregarde Investigation by Mercedes Lackey

"Diana Tregarde finds unexpected danger in New York--a rock band of psi-vampires that feed on strong negative emotions--and soon this practicing witch allies herself with Andre LeBrel, a true vampire who intends to destroy this musical menace." (from Amazon.com)

Paperback Info: ISBN 0812522729, Tor Books, 1994 (reissue)