Unity was born from a King holiday event 11 years ago that involved vocalists from M'kor and Kaighn Avenue Baptist Church.
The Camden congregation is no longer involved, but Unity has grown to include members of a half-dozen African American churches from central and South Jersey.
A creative collaboration has blossomed, as have many friendships - evident in the buzz of conversation and soulfulness of the music.
"You can feel it," founding member Evelyn Thomas says. "The choir started out as a way to convey Dr. King's message, but since then, it has kind of taken on a life of its own."
"It's just a love thing," the Somerset County resident adds. "We love singing with each other so much."
Thomas is among four music professionals who direct the choir and conduct segments of the program. The others are M'kor Shalom cantor Anita Hochman; Donavon Soumas, of Monmouth County; and Beverly Mondey-Collins, of Gloucester County.
At last Thursday's dress rehearsal, the singers and a quartet of instrumentalists - including drummer Ron Cunningham of Pennsauken, who has performed with Patti LaBelle - sounded magnificent.
They practiced an eclectic program of tunes that included pop ("We Are the World," "Put a Little Love in Your Heart") as well as traditional and contemporary Jewish and gospel selections such as "Behold How Good (Hine Ma Tov)" and "Every Praise."
Unity members say that while the differences between African American and Jewish music (and, of course, Christianity and Judaism) are profound, so are the connections between blacks and Jews.
Both communities have experienced a history of persecution and a long struggle for freedom. Each has been nurtured by a distinctive culture, both secular and spiritual.
"It's wonderful when you can blend these traditions together," says Mondey-Collins, whose daughter, Sydni, 14, also sings in the choir.
"We share a lot more than you might imagine," Hochman adds. "A love of God, a love of music, a love of praising God through music."
The mix of traditions was particularly evocative during a Soumas arrangement called "Freedom Medley" and "In This House," a showstopper.
"It works from the heart," Soumas says. "Everyone wants to be here and knows the value of coming together to celebrate the struggle. And we really like each other."
The collaboration has practical, as well as spiritual, benefits, says Sheila Goodman, a past president of M'kor.
She notes that Jewish members of the Unity Choir have shown their African American colleagues how to sing lyrics such as luh-khi-ehm.
"They taught us . . . how to clap, sing, and sway," Goodman says. "At the same time."