Williams will join the cast this April.
The civil rights activist visited the cast and saw the acclaimed show at the Brooks Atkinson Theatre.
Lang's opening night as the musical's latest Special Guest Star took place on February 11.
The man at the helm of lively moves in both After Midnight and A Christmas Story lights up the New York theater.
Guests also included Wynton Marsalis, k.d. lang, and Darlene Love.
Upon the opening of After Midnight, take a glance at the future Doubt Tony winner as she sang the most famous of show openers.
Jazz, gospel, R&B…'Tasia can do it all.
A first look at the new musical, live onstage.
The world-class band will perform jazz legend Duke Ellington's original arrangements in the Broadway ode to the Cotton Club.