With his last three albums Stevie Wonder has replaced Sly Stone as the most significant individual black innovator in the twin fields of R&B and rock. He has also replaced him as the most popular black music personality: Wonder’s appeal now crosses every boundary. His music always sounds free and, at his best, he does things no one else can. “Living for the City” has the most compelling — pounding, throbbing, unyielding — beat to be heard anywhere at all. And though that same cut’s audio montage would crumble in the hands of a lesser artist, he makes it work through the force of his personality. There is something complete about Stevie Wonder, and one senses that he is not only exceptionally important today, but will continue to be for as long as he chooses.