The classiest possible selection that isn't jazz or classical or clever and harmonious folk pickin', fiddlin' and singin' .
Although if you're in a more relaxed mood, try Dave Carter and Tracy Grammer, for the latter choice.
They're not as well known, but wonderful beyond my meager powers of description.
Well, actually, Dave is now simply beyond, sadly.
But seriously, when I run long distances, they are often in my ears. Tracy sings like an angel and is a fine instrumentalist, and Dave was a lyricist with few rivals and damned good with an instrument, as well. And his singing sorta grows on a person.
First album I ever listened to from them was Drum Hat Buddha. It's still a favorite, years later.
And you'll look far and wide before you find any musicians that are smarter than they are.
Crossfire hurricane. Listen for those words, which apparently appeared in their music long before I heard them elsewhere. Interesting, no?