Abundant Music - Generate royalty free music with a simple but very powerful procedural music creator
GNU Solfege - GNU Solfege is free music education software.
AIVA - The AI composing emotional soundtrack music
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
WolframTones - Listen to what I just found in the WolframTones music universe
Meludia - Listening exercises and to sharpen your ear and music theory skills