Ricci Adam’s MusicTheory.net earns my highest recommendation for practicing all sorts of music skills. My absolute favorite aspect of this site is that you can DOWNLOAD it and use it away from an internet connection, with all of its functionality intact.

What can you learn/do on this site?

• How to read music: clefs, scales, durations, rhythm, accidentals, intervals and chords. All here, all the time.
• Learn the piano keyboard.
• Learn and quiz yourself on the guitar fretboard.
• Learn to recognize sight-singing and dictation intervals by listening and quizing yourself.
• Practice brass fingerings.
• Generate chords, music paper or even twelve tone matices.
• . . . and more.

Absolutely invaluable for students of ear training and theory courses around the globe. Thank you Ricci!