Actor and director Spike Lee joins actress Debbie Allen on a journey in search of the perfect vocal performance. They travel through Brooklyn as different groups duel, jam and rehearse together, without the benefit of an instrument other than their own voices, culminating in an all-star a cappella concert. The film, the directorial debut of cinematographer Ernest Dickerson , features contemporary vocal groups such as the Persuasions and Ladysmith Black Mambazo.