An invocation of something from another place.
I was listening to a prison song recorded by Alan Lomax called "Rosie", and started playing with a piece of it in Audacity.
I believe "Rosie" is in Volume Two of a collection called "Prison Songs: Historical Recordings From Parchman Farm 1947-1948".
This piece also contains the following clips from Freesound.org:
monster drone from Dan Oberbauer ( http://www.freesound.org/people/dj%20chronos/ )
ululating from benboncan ( http://www.freesound.org/people/Benboncan )
"The Lorax", by Dr. Seuss,
"Blood Music", by Greg Bear,
"At The Mountains of Madness", by H.P. Lovecraft.