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