Rhythm Exercises- Notation for drills, rudiments and etudes for practicing rhythm. By Nick Marshall.
Star Theory- Free preparatory syllabus in music theory and orchestration.
The Anatomy of a Fugue- An outline of the substantials of a fugue based on Hugo Norden's "Foundation Studies in Fugue." Topics include counterpoint, subject, answer, and stretto.
The Tonal Centre - Tonality- Interactive site for music composers and theorists which explains and demonstrates some of the key concepts of tonality; including chords, scales, cadences, and modulation.
Theory of Music with Ted Kirk- Resources for learning and teaching music theory to grade 5 of the Associated Board (UK).