AP Music Theory connects written notation, ear training, harmony, and musical structure. This cheat sheet gives students a compact reference for the symbols, patterns, and labels used most often on the exam. It is useful for reviewing analysis skills, checking written work, and building confidence with common tonal-music conventions.
Key Facts
- In treble clef, the staff lines from bottom to top are E, G, B, D, F, and the spaces are F, A, C, E.
- In bass clef, the staff lines from bottom to top are G, B, D, F, A, and the spaces are A, C, E, G.
- Major scale pattern is W W H W W W H, where W means whole step and H means half step.
- Natural minor scale pattern is W H W W H W W, harmonic minor raises scale degree 7, and melodic minor raises scale degrees 6 and 7 when ascending.
- A major triad has root, major third, and perfect fifth, while a minor triad has root, minor third, and perfect fifth.
- Common Roman numerals in major keys are I, ii, iii, IV, V, vi, and vii°, with uppercase for major chords and lowercase for minor or diminished chords.
- A dominant seventh chord is written V7 and contains scale degrees 5, 7, 2, and 4 in a major key.
- A perfect authentic cadence is V or V7 to I with both chords in root position and scale degree 1 in the soprano on the final chord.
Vocabulary
- Key signature
- A set of sharps or flats at the beginning of a staff that shows the tonal center and diatonic pitch collection.
- Interval
- The distance between two pitches, named by number and quality such as major third or perfect fifth.
- Roman numeral analysis
- A system for labeling chords by their scale-degree root and quality within a key.
- Cadence
- A harmonic ending or pause that gives a phrase a sense of closure or continuation.
- Inversion
- A chord position in which a note other than the root is the lowest sounding pitch.
- Nonchord tone
- A pitch that is not part of the current chord and usually resolves by step or follows a recognizable melodic pattern.
Common Mistakes to Avoid
- Confusing key signature with temporary accidentals is wrong because accidentals can create chromatic notes without changing the overall key.
- Counting only semitones for intervals is wrong because AP Music Theory requires both interval number and quality, such as M3, m3, P5, or A4.
- Writing uppercase Roman numerals for every chord is wrong because numeral case shows chord quality, with uppercase for major and lowercase for minor or diminished chords.
- Ignoring chord inversion is wrong because figured bass symbols such as 6, 6/4, 7, 6/5, 4/3, and 4/2 identify the bass note and affect voice leading.
- Calling every V to I motion a perfect authentic cadence is wrong because a PAC must use root-position V or V7 to root-position I and end with scale degree 1 in the soprano.
Practice Questions
- 1 In the key of D major, identify the notes in the V7 chord and write its Roman numeral.
- 2 What is the interval from F up to C sharp, including both number and quality?
- 3 In A minor, write the ascending melodic minor scale using note names.
- 4 Explain why the progression ii6 to V7 to I creates a strong sense of tonal direction in a major key.
Understanding AP Music Theory Reference
Reading music quickly depends on seeing relationships, not memorizing each note from zero. A clef tells you where one reference pitch sits on the staff. From that point, every nearby line or space follows the musical alphabet.
Ledger lines extend this pattern above or below the staff. Watch for octave displacement marks, since they change sounding pitch without changing the written note names. Accidentals need careful attention.
A sharp, flat, or natural written beside a note usually lasts until the end of that measure for that pitch in that octave. A key signature works differently. It sets the usual collection of sharps or flats for the whole passage, unless a temporary accidental changes one note.
Intervals have two parts. The number comes from counting letter names inclusively. The quality comes from the distance in half steps.
This prevents a common mistake where students count only staff spaces or only piano keys. For example, two notes may use the same number of letter names but have different qualities because of accidentals. Inversions give another useful check.
When two intervals invert, their numbers add to nine. Their qualities pair in predictable ways.
Major becomes minor, augmented becomes diminished, and perfect stays perfect. Interval recognition matters in sight singing because the first note gives a starting point, while each later interval gives the next target.
Harmony is easier to analyze when you first identify the key, then sort notes into vertical groups. Find the root of each chord even when that root is not the lowest sounding note. The lowest note determines inversion, which affects the label used in figured bass and harmonic analysis.
Chord members also have jobs. The third usually tells whether a triad is major or minor. The seventh in a seventh chord often creates tension that wants to move by step.
In four-part writing, voices should move smoothly when possible. Leading tones tend upward toward the tonic.
Chordal sevenths usually move downward. Parallel perfect fifths and octaves weaken the independence of voices, so check consecutive pairs of soprano, alto, tenor, and bass notes.
Cadences are not just chord names at the ends of phrases. They create degrees of arrival, pause, or continuation. The strongest endings use dominant function to direct the ear toward tonic, yet the melody note and bass note can make that arrival sound more or less complete.
A phrase ending away from tonic may sound unfinished even if the rhythm slows down. When analyzing a score, mark phrase boundaries before assigning labels. Then listen for repeated motives, sequences, and changes in harmonic rhythm.
On an exam, written answers improve when each label matches the notes actually present. Ear training improves when students sing scale degrees, especially the pull from seven to one and from four to three. These small motions explain much of tonal music.