Listening to "Someday We'll All Be Free"...definitely an underrated singer, regardless of genre. This song matches anything from "What's Going On", "Songs In The Key Of Life", etc.
Click here:
http://h1.ripway.com/idigworms/12DonnyHathaway-SomedayWellAllBeFree.mp3"Love Love Love", another good tune with a Marvin Gaye vibe:
http://h1.ripway.com/idigworms/DonnyHathaway-07-LoveLoveLove-frc.mp3