in displaying a music score by using a computer , there is provided a function for matching an in - music position being updated in a computer with an in - music position being played . according to the in - music position , display update is controlled . space of music score display is divided into several partitions . the timing of updating each partition is defined as the moment when the in - music position in the computer has arrived at the position in the page obtained by predetermined function from the position of the page divided and the partitions are successively updated . thus , it is possible to realize smooth display update capable of displaying the preceding partition and holding the display with a sufficient width before and after the position being played . here , a plurality of timing input means are provided for matching the in - music position required here , so that a trace shift in the lower level can be corrected by means having a higher - level reliability when necessary . when playing in concert , the music score is different for each part but the display update can be controlled by supplying the in - music position information .