Have You Met My Collaborator? He’s So Classic, He’s Dead.

Remaking a vintage musical for the 2020s takes guts, sensitivity and perhaps a medium. On Broadway, Off Broadway, in special events and out of town, living authors are collaborating with dead ones. Amber Ruffin is revamping the book of “The Wiz,” the 1975 musical that is itself a revamp of “The Wizard of Oz” with Black characters. Richard LaGravenese and Daniel Koa Beaty are overhauling John O’Hara’s 1940 script for “Pal Joey” while keeping the classic songs Rodgers and Hart wrote for it — along with a bunch borrowed from the duo’s other shows. And John Weidman’s revisal of the 1962 musical “I Can Get It for You Wholesale” finds him working intimately with an unexpected yet familiar old name.

Tinkering with the books of revivals is of course nothing new. Some otherwise viable shows, like “Annie Get Your Gun,” need surgery because their racial or gender assumptions are now unacceptable. Others, from a time when musicals were not meant to be models of dramaturgical cohesion or gravitas, have plot holes the size of canyons, or a general air of silliness no longer in style. (Pretty much anything before 1943.) Others, like “Show Boat,” are merely falling out of copyright, with heirs eager to find a way to remonetize their property.

And some — well one — are “Here We Are,” the musical Stephen Sondheim was working on when he died in November 2021. News from the Sondheim batcave is sparse, and we don’t know who or what has completed the work that the songwriter, five days before his death, told my colleague Michael Paulson was unfinished. Still, something by Sondheim, and presumably still based on the Luis Buñuel films “The Discreet Charm of the Bourgeoisie” and “The Exterminating Angel,” is scheduled to show up at the Shed starting Sept. 28. Directed by Joe Mantello and with a book by the comic playwright David Ives, it will reflect a very unusual collaboration indeed.

But most of the post-mortem collaborations this season are of a different sort. Weidman, who wrote the books for Sondheim’s “Pacific Overtures” and “Assassins,” says his work on Classic Stage Company’s revival of “I Can Get It for You Wholesale,” which opens in October, isn’t a collaboration at all, but a conversation. And the person on the other end of the conversation is his father.