Mantra is creation by Word
The word is a sound expressive of the idea. In the supra-physical plane when an idea has to be realised, one can by repeating the word-expression of it, produce vibrations which prepare the mind for the realisation of the idea. That is the principle of the Mantra and of japa. One repeats the name of the Divine and the vibrations created in the consciousness prepare the realisation of the Divine. It is the same idea that is expressed in the Bible, God said, Let there be Light, and there was Light. It is creation by the Word. – [Sri Aurobindo]
The recoding of this mantra (Om Namo Bhagavate) was done in the Amphitheater (Matrimandir). Joy and Agni (acoustic guitar) guided the chanting.