MUSIC

The Colorado String Quartet--on tour in Anchorage, Ala.-- dropped out of sight in mid-performance Monday, leaving a gaping hole in the stage. In the middle of Shostokovich’s String Quartet No. 5 in B flat, the four acclaimed New York musicians suddenly began to sink. Stagehands discovered that pranksters had rigged the stage elevator to send the movable portion of the stage down. “The musicians kept on playing for as long as it made any sense to,” said a spokesman for the concert’s sponsor, the Anchorage Concert Assn., and added that measures will be taken to guard against future pranks. After the unexpected disappearing act, the musicians made their way back up to the stage and completed the performance.