Soprano Elizabeth Connell, who was to sing the title role in Elektra, will be the soloist in the Prelude and Liebestod from Wagner's Tristan und Isolde and the final scene from Strauss's Salome.
A spokesman said that the program change was part of the orchestra's efforts to cut costs and reach a balanced budget for 2005-06. The group has also canceled its interAct! series, which featured themed performances with commentary.
The dates of the program have been changed from Saturday and Monday, March 11 and 13, to Friday and Saturday, March 10 and 11. Both concerts begin at 8 p.m.