Learn music theory & train your ears regardless of your musical experience. Solfej offers over 60 Practical lessons. No more Wikipedia/YouTube rabbit holes. New lessons added every month.
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Metronaut - An app to help you play classical music
Meludia - Listening exercises and to sharpen your ear and music theory skills
Flat for Education - The best way to teach music to your students
Perfect Ear - A simple yet advanced application for improving your solfege skills.
Scribd Sheet Music - All the sheet music, books and comics you want for $9/month