Open Music Theory is a natively-online open educational resource intended to serve as the primary text and workbook for undergraduate music theory curricula. OMT2 provides not only the material for a complete traditional core undergraduate music theory sequence (fundamentals, diatonic harmony, chromatic harmony, form, 20th-century techniques), but also several other units for instructors who have diversified their curriculum, such as jazz, popular music, counterpoint, and orchestration. This version also introduces a complete workbook of assignments.