and helps with developing skills of playing and singing notes.
Simply: users looks at piece of a score, plays it, Nootka is listening to it, checks and shows was it played well. All in real time.
Market link: net.sf.nootka
Web site: http://nootka.sf.net
Source code: https://sourceforge.net/projects/nootka/files/Nootka-1.2.7/nootka-1.2.7-source.tar.bz2/download
Code license: GPLv3