#MuseScore wowed me at #Fosdem. What it does is provide you with a way to provide all kinds of functionality with a music score.
When you have a video with a synchronised score, it becomes possible to do karaoke on the piano or the guitar. The format is some kind of XML and the output needs to be rendered. The rendering is not rocket science; it needs to be done and from then on it just needs to be used.
Just think the fun we can put into our articles when people can read about music and just play.