Live musical accompaniment can have a magical effect on a dance performance. That was the case Friday night at the Cowles Center when the legendary a cappella ensemble Sweet Honey in the Rock stepped on stage as part of Threads Dance Project's "Body & Soul: An Evening of Dance." Their heavenly vocals lifted up movement that earlier in the evening had struggled to take flight.

Choreographer Karen L. Charles featured three works with Sweet Honey. Karen Christ, Aneka McMullen, Kara Motta and Betsy Schaefer-Roob performed "Memories" (2011) with generous spirit, giving the light-as-air movement a springlike lift. Most poignant was "Childless Mother" (2010-11). Sweet Honey sang of grief, their vocals delving deep into the primal pain that comes when a mother loses a child. The choreography is infused with loss and confusion, but also defiance. As Sweet Honey's lyrics lament, some children's deaths are the result of social injustice.

The world premiere of "Dust to Dust" by Charles is an exploration of life's fleeting aspects. Sweet Honey's accompanying lyrics remind us that we never know how the day will end or what the next day will bring. With the entire Threads troupe onstage (dressed in stunning swirling skirts created by Annie Cady) the impact was celebratory even though death was the main subject. Here Charles demonstrated her strong ability to summon up a stirring collective spirit.

The other works on the program did not resonate as powerfully. "Call" (2013), about the love/hate relationship between dancers and their craft, felt unfocused, perhaps deliberately so because it explored uncertainty. Whether intentional or not, this piece never quite came together as an exploration of artistic anguish and the performances by the company members were uneven in skill.

The evening opened with 2012's "Humanity & Elysian fields Avenue," a response to Hurricane Katrina's toll. Such intense subject matter could inspire many emotions, but most of this work comes off as oddly flat. Toward the end, however, Charles gave the piece the expressive boost it needed by having the dancers come together as if deconstructing a jazz funeral parade. It was somber, but the music by Terence Blanchard and Charles' choreography drew upon the inner strength of the Katrina survivors. This last section is the real tribute — a salute to hope in the face of adversity.

Caroline Palmer writes about dance.