Captain Chords - Write chord progressions in your favorite DAW
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Odesi - ODESI is a music sketchpad that exports your projects to Audio and MIDI.
Meludia - Listening exercises and to sharpen your ear and music theory skills
RapidComposer - MusicDevelopments RapidComposer: Music Prototyping and Automated Composition Software
Perfect Ear - A simple yet advanced application for improving your solfege skills.