 He was also featured in Chaka Khan's cover of Prince's "I Feel For You", alongside Melle Mel, playing his signature harmonica.In roughly the same period he was also featured on harmonica on Eurythmics' single, "There Must Be an Angel (Playing with My Heart)" and Elton John's "I Guess That's Why They Call It the Blues".Wonder was in a featured duet with Bruce Springsteen on the all-star charity single for African Famine Relief, "We Are the World", and he was part of another charity single the following year (1986), the AIDS-inspired "That's What Friends Are For".