“Company” leading man Adrian Lester makes history this week as the first black male on either side of the Atlantic ever to take a starring role in a Stephen Sondheim musical. The production, directed by Sam Mendes, opens Dec. 13 at the Donmar Warehouse.

“Sam doesn’t see age or color at all; he’s a bit of a Declan on that point,” says Lester, 27, paying tribute to the two directors who have cast him in Sondheim – Mendes and, earlier, Declan Donnellan, for whom he played Anthony in “Sweeney Todd” at the National.

What difference will a black Bobby make to the show? Very little, say its director and star, not least since the Donmar production is set in the present, not in 1970. “Because the man you see Adrian with in the first scene is Clive” – Clive Rowe, the huge-voiced black Mr. Snow from the National’s “Carousel” – “you get the sense of a modern world, a multiracial group,” says Mendes.

The casting has necessitated one script change: Marta’s question to Bobby, “How many blacks do you know?” is now a query about gays – “the point being,” says Lester, “that Marta knows the diversity of people you can meet in New York and Bobby knows none of them.” (The casting, and script change, were made, of course, with the blessing of Sondheim and “Company” book author George Furth.)

With a hefty advance just under £135,000 ($205,000), the run is scheduled through March 2; any decision about a commercial West End transfer will be made around Jan. 10.

Final Sondheim note: Maria Friedman is expected to be named shortly as the star (with Michael Ball) of the West End premiere in March of “Passion.”