"Our company would have loved nothing more than to celebrate the holiday with the audience and their families, but the priority is the health and wellness of the cast, crew, and audience," the show's Twitter feed said Friday.
"The evening performance on Saturday, December 25 and matinee performance on Sunday, December 26 of Broadway's The Music Man have been canceled due to breakthrough COVID-19 cases. All tickets for the canceled shows will be refunded at the point of purchase."
Deadline.com said Foster tested positive for COVID-19 and had to drop out of Thursday's and Friday's performances. The shows went on with an understudy playing Foster's role.
Audiences, crews and performers for all Broadway productions are required to be vaccinated for the coronavirus, but breakthrough cases have caused The Lion King, Aladdin, Hamilton, Dear Evan Hansen, Aladdin and Harry Potter and the Cursed Child to cancel performances in recent weeks.