J.J. Cale's laconic delivery has been hugely influential: after hearing him in the 70s, Eric Clapton quite clearly imitated him for a good while (think "Lay Down Sally"), and Mark Knopfler's entire vocal style (as well as his finger-picked electric guitar) can be seen as derived from Cale.

Cale's classic records "Really", "Naturally" and "Okie" are full of minimalist gems that sound casually tossed-off but are in fact little songwriting masterpieces.