PianoBooster is a free (Open Source) program that plays Standard Midi Files and allows you to change the speed of playback and transpose the music etc. There is a scrolling musical stave that shows the notes for just one part from all the parts in the complete musical arrangement.

PianoBooster has been designed to allow you to play along on a midi piano keyboard with the scrolling notes shown on the screen. The notes you press on the keyboard appear as coloured lines on the musical stave, the colour of which depends whether you have pressed the right or wrong note.

A different musical instrument sound is used for your playing depending whether you are playing the right or wrong notes. This feature also allows PianoBooster to be used with printed sheet music so you can hear if you are playing the right notes while at the same time keeping your eyes on the printed score. The music accompaniment will automatically wait for you to find and play the correct notes in the piece.