When it comes to R&B, the gold standard is indisputably Stevie Wonder. Maturing out of his teenage years, he started approaching deeper themes beginning on 1971’s Where I’m Coming From. The influence of his in-the-pocket, one-man-band musicianship on Songs in the Key of Life remains inescapable. From the joyous buoyancy of “Isn’t She Lovely” to the deep funk of “Sir Duke” to the melancholy of “Joy Inside My Tears” and the beauty of “Saturn,” the blueprint for so much of the R&B to come sprang from the creativity of Wonder in his mid-20s.