25 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Check the approach AND the resolution. Every non-chord tone is defined by both directions of motion: never judge by just one side.
Suspension vs. retardation comes down to direction. Both hold over a dissonant tone; only whether it resolves down or up differs.
Strip out the ornaments to find the real harmony. Removing non-chord tones reveals the underlying chord for Roman-numeral analysis.
Read the explanations even when you're right. Each one reinforces a fact that often returns in a different form on the exam.