Ms. Norman’s script has no overarching framing device — no “I remember” or “Dear Reader” structure — yet the effect here is of a story coming to life in the telling. All those chairs are stages from which yarns can be spun. The first words we hear have the plangent resonance of childhood remembered: “Hey, sista, whatcha gon’ do?”

The question is sung by Celie (Ms. Erivo) to her sister, Nettie (Joaquina Kalukango); it’s part of a habitual game-playing chant, reminding us that, in many ways, these girls are still children. Yet Celie, at 14, has already borne (and lost) two babies by the man she believes to be her father (Kevyn Morrow). Soon she will be sold into marriage to the whip-wielding Mister (an astringent Isaiah Johnson), who reminds her that she is poor, black and ugly — and trapped.

The story of Celie’s liberation is borne on a river of fluidly intermixed songs and spoken words that, as is often the case in cherished family anecdotes, bypasses long stretches of years and brings isolated events into dominant relief. If the story sometimes feels awkwardly tall, especially its wish-fulfilling second act, the musical forms it takes seem convincingly indigenous to its time and place.

There is, inevitably, gospel call and response, the devotional fervor of which Celie comes to resent (nobody’s answering her prayers) and later to embrace on her own terms. Fieldwork songs figure, too, reflections here of Celie’s domestic slavery. Then there are the songs of resistance, embodied with verve by two very different women who help Celie learn her own strength: Sofia (Danielle Brooks) and Shug Avery (Ms. Hudson).

Portrayed as a homemade steamroller by the wonderful Ms. Brooks (of “Orange Is the New Black”), Sofia is the strapping wife of Harpo (Kyle Scatliffe), Mister’s son, and she’s not about to let any man boss her around. Shug, a flashy honky-tonk singer, is Mister’s sometime mistress, though no single lover owns her. Usually, she’s played as a brazen, Bessie Smith-style blues diva.

Ms. Hudson, though, brings a softening vulnerability to Shug that suggests that, like Celie, she’s been partly pushed into what she’s become by how men regard her. Best known as a recording artist and “American Idol” finalist (who also won an Oscar for the movie “Dreamgirls”), Ms. Hudson radiates a lush, supple stage presence that is echoed by her velvet voice.

We see the tenderness — and the need to be cared for — that Celie sees in Shug. And we understand why these mismatched women would fall for each other. Their climactic duet at the end of the first act (“What About Love?”), for all its gentleness, is still the most sensual love song on Broadway this season.