For more technical lessons and practice, including piano work and ear training.
Can be difficult to understand without a music background.
A website full of simple yet fun games all designed around music. It includes theory, history, ear training, and everything in between.
Great for kids or those who want to play a game.
This is a great online tuner for guitar, piano, and other treble clef instruments.
After you've learned about the "Science of Sound", play around with this tone generator. You can even make it go higher and lower than the human ear can hear.
Be careful with your speakers and don't hurt your ears!