Glossary
6/4 Chords (doubling)
A specific rule stating that in a second inversion triad (6/4 chord), the bass note (which is the fifth of the chord) must always be doubled.
Example:
For a C major 6/4 chord (G-C-E), the G in the bass must be doubled according to the 6/4 chords doubling rule.
Acceptable Progressions
Standard and predictable sequences of diatonic chords (like tonic, supertonic, subdominant, dominant) that create coherent harmonic movement.
Example:
A typical acceptable progression might move from I to IV to V to I, creating a sense of departure and return.
Authentic Cadence (AC)
A cadence that moves from a V (or vii°) chord to a I (or i) chord, providing a strong sense of resolution.
Example:
Most classical pieces conclude with some form of Authentic Cadence to provide a definitive ending.
Bass Leaps
Larger melodic intervals in the bass line, which are more common and acceptable than in upper voices, often outlining triads.
Example:
The bass line might use a leap of a perfect fifth from C to G to clearly define a C major chord moving to a G major chord.
Bass Line
The lowest melodic line in a composition, which provides the harmonic foundation and often features more leaps than upper voices.
Example:
A strong and clear bass line is crucial for defining the harmonic progression of a piece.
Bass Rhythms
The rhythmic patterns used in the bass line, typically quarter notes but can vary to half or eighth notes.
Example:
While quarter notes are common, varied bass rhythms can add interest and drive to a piece.
Cadences
Musical punctuation marks that provide a sense of conclusion or pause at the end of a phrase or section.
Example:
Identifying different types of cadences helps to understand the structure and emotional flow of a piece.
Common Practice Period (CPP)
A historical era in Western music, roughly 1650-1900, during which specific harmonic and voice leading rules were established and widely used.
Example:
Most of the harmony rules you learn in AP Music Theory, like avoiding parallel octaves, stem from the Common Practice Period.
Common Tones
Notes shared between two consecutive chords; these notes should ideally be kept in the same voice for smooth transitions.
Example:
When moving from C major (C-E-G) to G major (G-B-D), the G is a common tone and should ideally be held by the same voice.
Contrary Motion
Two voices move in opposite directions, which is highly favored in voice leading for creating independence and balance.
Example:
If the bass line descends while the soprano ascends, they are moving in contrary motion, a common and effective voice leading technique.
Cross-Relations
A chromatic alteration in one voice that immediately follows the natural form of the same note in another voice, often creating an awkward or harsh sound.
Example:
In C minor, if the alto sings an E-flat and the soprano immediately sings an E-natural, this creates a cross-relation.
Deceptive Cadence (DC)
A cadence where a V chord resolves to a chord other than the tonic (most commonly vi or VI), creating a surprising or 'deceptive' resolution.
Example:
The sudden shift from V to vi in a Deceptive Cadence can add an unexpected twist to a melody.
Dominant (function)
Chords (primarily V and vii°) that create tension and a strong pull towards the tonic, leading to a sense of arrival.
Example:
The G major chord in C major has a dominant function, strongly leading the listener's ear back to C major.
Double the Root
The primary rule for doubling in triads, where the root of the chord is repeated in another voice, whenever voice leading allows.
Example:
In a C major triad, you would typically double the root (C) to fill out the four voices.
Doubling Rules
Guidelines for which note to repeat in a triad when writing for four voices (SATB), as triads only have three unique notes.
Example:
Understanding doubling rules is essential for correctly completing SATB voice leading exercises.
Half Cadence (HC)
A cadence that ends on a V chord, creating a feeling of incompleteness or a musical question.
Example:
A phrase ending on a Half Cadence leaves the listener expecting more music to follow.
Harmonic Progression
The purposeful movement of chords from one to another, creating a sense of direction and structure in music.
Example:
The standard I-IV-V-I is a fundamental harmonic progression that provides a strong sense of resolution.
Imperfect Authentic Cadence (IAC)
A weaker form of the authentic cadence, where either the V or I chord is inverted, or the soprano voice ends on a non-tonic pitch.
Example:
If a V6-I progression concludes a phrase, it's an Imperfect Authentic Cadence because the V chord is inverted.
Implied Chords
The underlying harmonies suggested by a melodic line, even if not all chord tones are explicitly present.
Example:
Even if only a melody is given, you can often discern the implied chords by analyzing the strong beats and melodic contours.
Leading Tone
The seventh scale degree in a major or harmonic minor key, which has a strong tendency to resolve upward by step to the tonic.
Example:
In G major, the F# is the leading tone and almost always resolves up to G, especially in the soprano or bass.
Leading-Tone Seventh Chords (ⅶo7 and ⅶø7)
Seventh chords built on the leading tone (vii°7 or viiø7), which function as dominant substitutes and often resolve to the tonic.
Example:
A leading-tone seventh chord can create a strong pull to the tonic, similar to a V7 chord, but with a slightly different color.
Melodic Intervals
The distance between two consecutive notes in a single melodic line, with certain intervals (like augmented or diminished) generally avoided.
Example:
Good voice leading emphasizes smooth melodic intervals like seconds and thirds, rather than awkward leaps.
Non-Tendency Tones
Chord tones that do not have a strong melodic tendency to resolve in a specific direction, making them suitable for doubling.
Example:
Unlike the leading tone, the root and fifth of a chord are generally non-tendency tones and can be doubled.
Oblique Motion
One voice remains stationary (common tone) while another voice moves, creating a stable and smooth connection between chords.
Example:
When moving from a C major to an F major chord, the C in the soprano can stay put while the other voices move, demonstrating oblique motion.
Omitted Fifth (in V7)
In a root position dominant seventh chord (V7), the fifth of the chord can be left out, and the root is doubled instead.
Example:
When writing a V7 chord, you might use an omitted fifth to ensure proper voice leading into the tonic.
Outer Voice Dissonances
Harmonic intervals between the soprano and bass voices that are considered dissonant, with augmented and diminished intervals (especially tritones) generally avoided.
Example:
Careful attention must be paid to outer voice dissonances to ensure the overall harmony sounds balanced and pleasing.
Parallel Fifths and Octaves
Consecutive perfect fifths or octaves between the same two voices, which are strictly forbidden in Common Practice Period voice leading due to their undesirable sound.
Example:
Accidentally writing parallel fifths and octaves is a common voice leading error that makes the harmony sound thin or archaic.
Parallel Motion
Two voices move in the same direction by the same interval, often resulting in undesirable sounds like parallel fifths or octaves.
Example:
Composers generally avoid parallel motion between the bass and soprano when they both move by a perfect fifth, as it can sound hollow.
Perfect Authentic Cadence (PAC)
The strongest type of cadence, where both the V and I chords are in root position, and the soprano voice ends on the tonic scale degree.
Example:
A piece ending with a V-I progression where both chords are root position and the melody lands on the tonic is a Perfect Authentic Cadence.
Plagal Cadence (PC)
A cadence that moves from a IV or iv chord to a I or i chord, often called the 'amen' cadence due to its common use in hymns.
Example:
The 'amen' at the end of many hymns is a classic example of a Plagal Cadence.
Repeated Bass Notes
The same note held or re-articulated in the bass, acceptable on strong beats, at the start of a phrase, or as a suspension.
Example:
A sustained pedal point often features repeated bass notes to anchor the harmony.
Repeated Harmonies
The repetition of the same chord, which is acceptable on strong beats or at the beginning of a phrase.
Example:
A composer might use repeated harmonies at the start of a phrase to establish the tonic before moving on.
Resolve Downward (for 7th)
The rule that the chordal seventh must typically move down by step to the next chord, unless it is suspended or part of a specific progression.
Example:
In a G7 chord, the F (the seventh) must resolve downward to E in the subsequent C major chord.
SATB
An acronym for Soprano, Alto, Tenor, and Bass, representing the four standard vocal parts in choral music, arranged from highest to lowest.
Example:
When analyzing a four-part chorale, you'll typically label the voices as SATB.
SATB Order
The standard arrangement of four vocal parts (Soprano, Alto, Tenor, Bass) from highest to lowest, which should be maintained to avoid voice crossing.
Example:
Maintaining strict SATB order prevents the alto from singing below the tenor, which can obscure the harmonic clarity.
Seventh Chord Rules
Specific voice leading guidelines for handling the chordal seventh, including how it should be approached and resolved.
Example:
Mastering Seventh Chord Rules is crucial for writing smooth and correct voice leading with V7 chords.
Similar Motion
Two voices move in the same direction but by different intervals, which is generally acceptable in voice leading.
Example:
In a chorale, the alto and tenor might move in similar motion, both ascending, but the alto by a step and the tenor by a third.
Stepwise Motion
Melodic movement primarily by steps (seconds), which promotes smooth and singable lines in individual voices.
Example:
To ensure a lyrical melody, a composer will often prioritize stepwise motion over large leaps.
Tonic
The first scale degree and the chord built upon it (I or i), serving as the stable 'home' key and point of resolution.
Example:
In the key of C major, C is the tonic note and the C major chord is the tonic chord, providing a sense of rest.
Voice Leading
The horizontal movement of individual melodic lines (voices) from one chord to the next, focusing on smooth and pleasing transitions.
Example:
When arranging a hymn, careful voice leading ensures each part flows naturally and avoids awkward jumps.