The mortal sin of “Amazing Grace” at the new Museum of the Bible is that it’s a musical without musicians — computer software somehow “plays” the score — but that’s not all. The largely true but plodding melodrama of John Newton, the British slave trader who ultimately repented and wrote the famous hymn, is so slow-moving and cliched that you’d swap it for a windy sermon.

The production launches the non-Equity touring version of the show that played Broadway in 2015, designed by Broadway veterans Eugene Lee (supplying a nifty nautical-themed set with Edward Pierce), Ken Billington (lights capable of suggesting sea storms) and Toni-Leslie James (18th-century costumes with breeches and laced bodices). But Christopher Smith’s book with Arthur Giron — and Smith’s power-ballad songs — are leaden from the opening narration that declares: “I was there. It’s a story that has to be told.”

Newton is portrayed as bitter at God over his mother’s death. His father is a slave-trading tyrant. Newton suppresses his gift for songwriting, to the consternation of the beautiful soprano who loves him. He’s saved from a shipwreck by one of his father’s longtime slaves. Guess the rest.

Director Gabriel Barre’s young cast, as usual with these ­non-Equity tours, ranges from promising to very good, though it’s impossible to reconcile its sturdy singing with the irritatingly tinny sound of the ­computer-processed score. The only real point of interest is the World Stage Theater in this expensive new museum: It’s a temptingly comfortable 472 seats, including a balcony. It’s also attractive, wrapping the audience in a wavy wall-and-ceiling curve that glows handsomely before the show.

The space is acoustically dead, though, which will dampen audience laughs and cheers come the day they really arrive, and which keeps the performers at an emotional distance even with the sophisticated, effective new sound system. The stage is small, too, with practically no backstage space or flyspace. Bible-themed scholars, choirs and other presentations will probably keep this a niche venue, not a rival (or partner) to Washington’s theaters.

Amazing Grace, music and lyrics by Christopher Smith, book by Christopher Smith and Arthur Giron. Directed by Gabriel Barre. About 2½ hours. Through Jan. 8 at the World Stage Theater in the Museum of the Bible, 400 Fourth St. SW. Tickets: $70-$100. Visit museumofthebible.org.

Read more at ‘Amazing Grace’ lumbers into the new Museum of the Bible.