Tony-winning star Jessie Mueller will depart the show this March.
The musical officially opened at the Stephen Sondheim Theatre on January 12, 2014.
Other parts in the musical will also be cast for the Broadway, touring, and international productions.
The trio appeared at the Apple Store in New York's SoHo to perform selections from Broadway's Carole King Musical.
The event is the culmination of six weeks of fundraising for Broadway Cares/Equity Fights AIDS.
Broadway creatives take listeners behind the music on their cast albums in a new Ghostlight series.
Harvey Fierstein hosted the ceremony, which toasted longtime theater industry professionals.
Mueller's Tony-nominated costars Jarrod Spector and Anika Larsen have also extended their contracts.
Bandstand is written by Robert Taylor and Richard Oberacker.
The celebration will take place on September 23.