Besides having the vision and wherewithal to frame his running commentary on America and the black condition inside the most hook-filled soul-pop ever (His most underrated song: "He's Misstra Know-it-All"), Wonder played a lion's share of the instruments here too. Not so easy on tape machines and analog punch-ins! But you already know all that.
So why are we raving about this record yet again? Why re-purchase one of the greatest albums ever? Well, 'cause you'll get the one that sonically trumps any other version, including those issued on vinyl, Japanese SACD and 24/96 hi-res download.
It's just the music, unblemished, with no added wonky EQ or compression, and manufactured by the Audio Fidelity folks, who happen to work wonders within the CD (and vinyl) format, utilizing the best, most recent digital-to-analog converters, which, you'll note, have come a long way in the digital age.