The "Great Comet" is getting a new star.
The casting choice is striking. It reflects a bet by Broadway that "Hamilton" alumni have ongoing, bankable box-office appeal (another member of the original "Hamilton" cast, Phillipa Soo, will star in an adaptation of "Amélie" opening in April). And it is the rare instance in which two black actors are leading the cast of a show that is not about black characters: Mr. Onaodowan will star opposite Denée Benton as Natasha.
Mr. Onaodowan, a son of Nigerian immigrants who was raised in New Jersey and took up acting when an injury ended his high school football career, will assume the role on July 3, the day after Mr. Groban's departure, and has committed to staying until Sept. 4. The musical, set in 19th-century Russia, is adapted from a section of "War and Peace" in which Pierre is a wealthy but dejected member of the Moscow elite.
Mr. Onaodowan, who goes by the nickname Oak, was recommended for the role by the musical's director, Rachel Chavkin; he starred in a 2014 production of a play about boxing, called "The Royale," when she directed it at the Old Globe Theater in San Diego.
Ms. Chavkin said she was also proud of the message the casting sent.
"It is emblematic of the world we have worked to put together, which is utopic and multiracial and pluralistic — it's a world that has space for everyone," she said.
Ms. Benton, who has repeatedly said that she had never thought a woman with her skin color would be cast as a Russian princess on Broadway, was similarly pleased.
The musical, powered by generally strong reviews and the enthusiasm of Mr. Groban's ardent fan base, has been doing well at the box office, grossing over $1 million most weeks since opening. But any time Mr. Groban has been absent, grosses have dipped, making the choice of his replacement important for the health of the show.
"The Great Comet" will be Mr. Onaodowan's fourth Broadway show — he was in a 2012 revival of "Cyrano de Bergerac" and in the 2014 musical adaptation of "Rocky," as well as in "Hamilton," which opened in 2015. Last year, he played Kristoff during developmental work on Disney's musical adaptation of "Frozen," but he said he was not continuing in that role.
Mr. Onaodowan first saw "The Great Comet" at opening night in November and was in the audience again on Tuesday night, when he intently studied Mr. Groban's movement and voice. "I have a lot of work to do," Mr. Onaodowan said after the show.
Mr. Groban, who is leaving to resume his recording career but expects to act again in the future, said he was delighted with the choice of Mr. Onaodowan to succeed him.