Stevie Wonder is one of the best-selling music artists in the world, he's won 25 Grammy Awards and an Oscar, and his activism has played a pivotal role in historic world events. In this very special episode of Sidetracked, recorded in a makeshift studio in a hotel on the edge of Hyde Park, Stevie tells Annie Macmanus about his approach to song writing, his adventurous childhood and his feelings about the word 'retirement'.