This is the first of four music theory lessons for Organ Performance Level 2, which should be completed in order. It may be studied concurrently with a registration lesson and a played assignment. Its concepts will be covered in the midcourse review (but not the final review).
Basic Materials in Music Theory
Study chapter 6 “Intervals” with the goal of internalizing each concept thoroughly. Study first, then work the mastery frames and supplementary assignments as needed.