AP Music Theory - Voice Leading (Part Writing) Error Detection Quiz - Five page quiz assesses commonly identified errors on released tests: parallel octaves/fifths, direct octaves/fifths, unequal fifths, octaves/fifths by contrary motion, overlapping voices, crossed voices, inappropriate spacing, doubled leading tone, and poor harmonic progression. - Test items include two-part and four-part harmony. While this quiz has been designed for use in the AP classroom, other classes may find them usefu