Story whise there is a caste of underground dwelling engineers who rarely venture to the surface who are taking care of that - via a giant pipe organ like music

Story whise there is a caste of underground dwelling engineers who rarely venture to the surface who are taking care of that - via a giant pipe organ like musical instrument/control console! They effectively play the whole planet using their inner understanding of the system and perfect musical hearing, keeping everything in perfect balance and harmony. (There are actually some other "engineer castes" such as the Salamanders that live on the floating islands and keep the ppanet warm. They are much less baddass but still rather hot blooded for some reason.)