Re-reading the OP, I see that Al is called an 'old-school' folksinger, not an 'old' folksinger. One could be 16 years old and still be an 'old school folksinger' if one did it right.

So, is there a new school of folksinging? If so, nobody told me. Could it be the Grateful Dead? Is Al old school because he doesn't have a rock-band setup?

Somebody please explain.