stand-up singers [who played no instruments]. Most of the big bands of the 1930s and '40s had folded, and instru- mental jazz,which achieved a cer- tain amount of general popularity during the swing era, lost much of its commercial appeal with the rise of bebop." Cole, Teachout says, chose to move with the times. In the fall of 1951, he quit playing jazz altogether and became a full-time singer. With songs like "Unforgettable," "Mona Lisa," and "Too Young," he...