Nestled amid a tale of hardship and torment, “Keep It Movin'” is a bright spot in the newly released adaptation of “The Color Purple.” Just as sisters Nettie and Celie (Halle Bailey and Phylicia Pearl Mpasi) are about to be torn from one another, they find a brief moment of respite and optimism as they sing to one another on the beach. “Nothing’s gonna take you down, oh / Just let it go / Life can never break your soul,” sings Nettie, instilling a feeling of hope that flickers and wanes in Celie as the film endures.

As one of the few original songs included in director Blitz Bazawule’s revival of “The Color Purple,” “Keep It Movin'” has already emerged as a focal point for the movie, which earned the second-biggest Christmas Day opening in history following its release on Dec. 25. Beyond its buoyant charms, it’s resonated beyond the...