"The Call of Ktulu" is the title of an instrumental composition by the heavy metal ban Metallica, released on their second studio album, Ride the Lightning in 1984. It was inspired by the writings of H. P. Lovecraft, particularly The Call of Cthulhu (The song's title is a phonetic spelling of Lovecraft's Great Old One Cthulhu.). The Call of Ktulu was Metallica's second recorded instrumental, and first in which the entire band played together.