Chaka Khan has been ordered by her doctors to go on extended vocal rest. The R&B great has cancelled four shows in June including the Capital Jazz Festival in Columbia, MD, the Pittsburgh International Jazz Festival, an appearance with the Columbus (OH) Symphony Orchestra and the concert Joni: A Portrait in Song in Toronto.

Khan, however, will not miss her June 10 induction into the Apollo Legends Hall of Fame at the Apollo Theater in New York. While Khan won't be able to perform, she will be honored by Erykah Badu, Patti LaBelle, Mary J. Blige and Deborah Cox.