Herman Melville once wrote “there is no quality in this world that is not what it is merely by contrast.” You cannot savor warmth without knowing the cold. And you can’t really fathom happiness unless you’ve known the full depth of sadness. Folk legend John Prine appears to understand this principle. His charmingly sweet songs like “In Spite of Ourselves” set you up for heart-rending ballads like “Sam Stone” and “Hello in There.” It can be such a roller coaster that even the lyrically light “Long Monday” seems like a heavy-duty painkiller. You can keep your young sad-sucker minstrels with their endless string of minor chords. I’ll take the old guy whose upbeat demeanor belies a lifetime of genuine heartache. by Brian Cook