All energies have a frequency of vibration.
The human only hears, sees and feelings a very limited band width of these universal energies. Phythagoras called the band widths which a human being could not see or hear 'the music of the spheres'. Within the human band width we see see colour, hear sounds, and feel that which is within the frequency of our senses. This is why art, music and drama are important fields of study in classical times. Phythagoras used mathematics and music theory to explain dynamic nature of the universe.