A system that allows the repositioning (scrolling) of the displayed portion of a music notation computer file in rasterized format, according to an internal or external time code/metronome, to constantly display the currently active part of the music notation file. By use of a corresponding data file describing the relative position of each music stave and form defining musical markings such as repeats or codas, a software application based on this invention can shift the displayed part of the entire music file to match the current played portion of the music notation file.