Jazz Theory Quiz now available for iOS in Apple App Store. Jazz Theory Quiz is an app which is designed to test your knowledge of music theory. The app has five quizzes: note functions, chords, diatonic chords by function, scales, and intervals. Answers can be entered using with a piano keyboard, or with named buttons, and are displayed on a staff. The quizzes are completely configurable- each quiz can be independently limited to particular keys and types; i.e. particular scales, chords, intervals, or functions. The iImprov series gives you the tools to understand the harmonic language of music- Jazz Theory Quiz helps to solidify your understanding of that language.