The Army of The Creator. Literally. There are millions and millions of angels, of many different types or choirs. It was said that when the loyal host descended upon Atlantis that they were so many they blotted out the very sun. That is subtracting the full third who rebelled with Lucifer. The angels exist only to serve The Creator. They may have different roles but essentially they are the Sons of The Creator as well as His most loyal servants. The music of Heaven is made up of nothing more than these millions of voices, singing eternally and unceasingly the praises of Him that they serve.