Re: the 70's? *ANYTHING* but the 70's!
Geoffrey W - we seem to be turning this thread into our own version of the Old Grey Whistle Test.
Jack Johnson is a contemporary singer/songwriter. The track I mentioned sounds rather like mid-70s Paul Simon ("Mother and Child Reunion", etc.), for better or worse - it's on Youtube if you care to listen. And I agree re Melanie! Besides, everyone knows Brand New Key was just a rip-off of the Wurzels. (...trollface icon for a reason...). Fairport Convention also excellent (Matty Groves, Rising for the Moon, Fotheringay).
Other good-but-lesser-known? 70s tracks I'd suggest you might check out: Medicine Head ("Rising Sun"), Labi Siffre (listen to "I got the..." from the 1m49s mark and reflect on how much royalties he's earning from Eminem), Bob Seger ("Turn the Page"), Don Fardon ("Indian Reservation"), Tanya Tucker's version of "Blood Red and Goin' Down", and J.J.Cale (whose version of "After Midnight" I think I prefer to Clapton's cover).