From memory...Owning ALL your masters would be the wisest choice for most musicians me thinks.
So Wonder would join an exclusive club such as Frank Zappa , King Crimson (Fripp) , Jethro Tull (Ian Anderson) , Neil Young , and Van Morrison .....to name a few.
Segue to Frank Zappa brings up the news (olde news actually) that he was recordng ALL of his live concerts in quad. According to BB JAN 12 74 Pg 18 plus Pg 30...... he had a four channel reel-reel and used it well..
Says mostly ambient for the rear channels however.
He had a stereo array over the drums and then a stereo array in front of the stage.
The track Ship Ahoy in quad is a good example.