GitHub Audio - Tracks events across GitHub to generate calming work music
Perfect Ear - A simple yet advanced application for improving your solfege skills.
GNU Solfege - GNU Solfege is free music education software.
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Meludia - Listening exercises and to sharpen your ear and music theory skills
LenMus - LenMus is a free program for learning music.