Bob Dylan has surpassed Walt Whitman as the defining American artist, celebrating the capacity for self-invention as the highest form of freedom.

"He not busy being born is busy dying," Dylan sang, in "It's All Right, Ma (I'm Only Bleeding)." Reinventer of folk music, voice of the 1960s, blues singer, rock star, born-again Christian, champion of gospel, country singer, old-style crooner, and now winner of the Nobel Prize for Literature, Dylan has found a million different ways to say the same thing. (He was born Robert Allen Zimmerman, and he sang, "You may call me Zimmy.")

I have been to just one Bob Dylan concert, about a decade ago. He concluded with his 1965 masterpiece, "Like A Rolling Stone," whose brutal lyrics seem to exult in the suffering of someone brought low. The song starts with a sneer: "Once upon a time you dressed so fine/You threw the bums a dime in your prime/didn't you?" The first stanza ends: "Now you don't talk so loud/Now you don't seem so proud/About having to be scrounging for your next meal."