In 1970, Griffin’s “Yours Till Forever,” written by a young songwriter named Kenny Nolan, skyrocketed to No. 1 on the Billboard pop singles chart. A band called The Exception, led by singer/bassist Peter Cetera, became one of the biggest acts of the decade and kicked off their international success with the horn-driven hit “My Mind Goes Traveling.” And, of course, the Lettermen, those pioneers of psychedelic pop, are still remembered for their ode to “Mr. Sun.” Okay, none of that really