The Futures are one of the most underrated vocal harmony group, if not the most underrated one. Love Will Be Around Forever from their 1975 Castles In The Sky album is a piece of art, both in regard to singing and arrangement. (Harry McGilberry of Temptations fame can be heard in the background.) Please see this post for more music of The Futures.
Love Lives On A Windy Hill (Castles In The Sky) is very special to me, and no other song has ever been on repeat as often as this gem.