Change Song by Lee Hoffman, Published by Doubleday & Company Inc, Garden City, 1972
 
"A lulling eco-logue about the Nightmen, menders of time and nature, who via special powers deal with time kinks and earthly disasters (storms, quakes, etc.) and keep the earth in synch. But there is dissension among them and Dorey, who is to be an apprentice, travels with the renegade Ryik to a point past the present where there may be no structure at all -- only to return and to realize that nature must be left alone to maintain her own balance. A pleasant alloy of medium and message which should find everyone attuned to Dorey's ""percept." - From Kirkus Reviews
 
7.10