The Cleveland Orchestra musicians are now on strike.

Union leaders announced on Sept. 24 that the orchestra would begin striking at midnight on Sept. 25 after musicians and management were not been able to reach an agreement on a new contract.

Thursday night, the orchestra performed a scheduled show, but orchestra officials said the Sept. 25 and Sept. 26 performances of music by Brahms, Liszt’s and Martinů would have to be canceled.

Since July, the two parties have been at the bargaining and apparently have made some progress on issues important to the musicians, including parental leave, workload, touring and hiring practices. However, the musicians’ collective bargaining agreement expired on Aug. 30 and on Sept. 2, the Orchestra and union agreed to extend that agreement through Sept. 23 while negotiations continued.

The union is demanding 25 percent in total salary increases over three years while Cleveland Orchestra management said in a statement that request “is simply not sustainable for the institution.”