John Legend performed a stunning, sparse Nina Simone medley: Watch

PARK CITY, UTAH – The life and times of Nina Simone were exposed to their bare and brutal roots in new documentary “What Happened, Miss Simone?”, which premiered tonight (Jan. 22) at the 2015 Sundance Film Festival. But the elegant sting of the late singer/songwriter's musical works continued even after the credits on the Liz Garbus-directed film stopped rolling.

Recently crowned Oscar nominee John Legend was on hand to perform a trio of songs from the Simone canon: “Lilac Wine,” “I Wish I Knew How It Would Feel To Be Free” and one of his covers staples “Don't Let Me Be Misunderstood.”

Legend called Simone “wonderful, powerful, dynamic” and among one of his favorite artists of all time. He played solo, seated at a grand piano with cascading red curtains behind him, singing with pitch-perfection and restraint — a gorgeous addendum to the warts-and-all offering that is “What Happened.”

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Sundance organizers have hosted a run of films that address ties of creative proclivity, mania and mental illness — recently, consider “Frank,” “Kurt Cobain: Montage of Heck,” “Running From Crazy,” and even “Whiplash.” Certainly, Simone's story falls into this category, with additional storylines of civil rights activism, her experience of racial bias and history of abuse.

The eye-opening element to Simone's fame and fall is how mental health alters the self-perception of success, and of happiness. What was reiterated over and over again in the film is that Simone's home was wherever her fingers were on piano keys, and her mouth behind a mic. What makes “What Happened, Miss Simone?” (the title is a line of prose written by Maya Angelou) into a celebration rather than solely a tragedy is the perseverance of her catalog.

So even as Legend rocked a neat suit with his lung-filled warble and approachable, classy stylings, you could hear the voice of Nina Simone: troubled, unique, divine.

“What Happened, Miss Simone?” plays all week at Sundance and will soon head to Netflix, which picked up the film for distribution. Legend is currently beating the Academy Awards trail for “Glory,” nominated for Best Original Song from the film “Selma” — the story to which, too, has ties to Simone's life journey.