Gershwin prizewinner Stevie Wonder-ful, as Tony Bennett likes to call him.

The last time Stevie Wonder played in town, his venue was the Lincoln Memorial. Before that, it was the Verizon Center. But last night, the room was considerably smaller, and the music exponentially more unique. At the Library of Congress’s Coolidge Auditorium, the overachieving 58-year-old pop/R&B legend, Rock and Roll Hall-of-Famer, Kennedy Center Honoree, and 25-time Grammy-winner led a reduced orchestra in the world-premiere performance of Sketches of a Life, a classical suite that’s been in the works for more than half of his.

Wonder began composing the piece in 1976, the year his seminal double-album Songs in the Key of Life hit No. 1 on the Billboard pop albums chart, and his creative powers were at their all-time peak. He finally finished the 25-minute symphony in 1994, inspired, he said, by Nelson Mandela’s election as president of South Africa. But the piece remained unheard outside of Wonder’s inner circle until last night, when Wonder offered it to an invitation-only audience that included Herbie Hancock and House Speaker Nancy Pelosi, among other Wonder intimates and politicos.