Colorado Symphony music director Jeffrey Kahane has been forced to cancel his weekend appearances with the orchestra, due to hypertension, according to a CSO spokesman.

The music director was to be soloist in Brahms' First Piano Concerto, with Marin Alsop conducting. In his place, Christopher O'Riley will play the Brahms concerto.

Kahane has been ordered to rest by his physician, causing the conductor/pianist to cancel additional dates this month with the Los Angeles Chamber Orchestra. The CSO spokesman said today that a decision will be made soon on whether Kahane will honor his scheduled conducting dates here later in March and into April.

Weekend performances will be at 7:30 p.m. Friday and Saturday, plus 2:30 p.m. Sunday in Boettcher Hall. Information: 303-623-7876.