A continuous low humming or buzzing sound (from the bee's humming sound).
  The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company.
Published by the Houghton Mifflin Company. All rights reserved.
  music that goes to the core of sound.
Genre that creates "soundscapes" where sound - and nothing else - is the protagonist.
  this term is used here as a tribute to Thomas Köner, Jonathan Coleclough and Marcus Obst