🎶AP Music Theory Unit 5 – Chord Progressions and Predominant Function

Key Concepts

• Chord progressions are sequences of chords that create harmonic movement in a musical composition
• Chords have different functions within a progression, such as tonic, predominant, and dominant
• Predominant chords are those that typically precede the dominant chord in a progression
• Common predominant chords include ii, IV, and vi in major keys, and ii°, iv, and VI in minor keys
• Chord progressions often follow established patterns, such as I-IV-V-I or I-vi-ii-V-I
• Analyzing chord progressions involves identifying the chords and their functions within the context of a musical piece
• Understanding chord progressions and predominant function is essential for composing, arranging, and improvising music

Chord Types and Functions

• Chords can be categorized by their function within a chord progression, which includes tonic, predominant, and dominant
• Tonic chords (I and vi in major keys, i and VI in minor keys) provide a sense of stability and resolution
• Predominant chords (ii, IV, and vi in major keys, ii°, iv, and VI in minor keys) create tension and lead towards the dominant chord
• Dominant chords (V and vii° in major keys, V and vii° in minor keys) create a strong pull towards the tonic and are often used for cadences
• Other chord types include secondary dominants, which are dominant chords borrowed from related keys to create additional tension and interest
• Chords can also be categorized by their quality, such as major, minor, diminished, and augmented
• The function and quality of a chord depend on its position within the scale and its relationship to other chords in the progression

Predominant Chords Explained

• Predominant chords are those that typically precede the dominant chord in a chord progression
• In major keys, the most common predominant chords are ii, IV, and vi
  • ii is a minor chord built on the second scale degree (e.g., Dm in the key of C major)
  • IV is a major chord built on the fourth scale degree (e.g., F in the key of C major)
  • vi is a minor chord built on the sixth scale degree (e.g., Am in the key of C major)
• In minor keys, the most common predominant chords are ii°, iv, and VI
  • ii° is a diminished chord built on the second scale degree (e.g., D° in the key of C minor)
  • iv is a minor chord built on the fourth scale degree (e.g., Fm in the key of C minor)
  • VI is a major chord built on the sixth scale degree (e.g., A♭ in the key of C minor)
• Predominant chords create tension and instability, leading the listener to expect a resolution to the dominant and then the tonic chord
• The ii and IV chords are often used in succession (e.g., ii-V-I or IV-V-I) to strengthen the predominant function

Common Chord Progressions

• Chord progressions are often built around the movement from tonic to predominant to dominant and back to tonic
• One of the most common chord progressions is I-IV-V-I, which is often used in popular music, folk, and rock (e.g., C-F-G-C in the key of C major)
• Another common progression is I-vi-ii-V-I, which features a predominant ii chord (e.g., C-Am-Dm-G-C in the key of C major)
• The 12-bar blues progression is a staple in blues, rock, and jazz, and typically follows the pattern I-I-I-I-IV-IV-I-I-V-IV-I-I
• In minor keys, the i-iv-V-i progression is common, with the iv chord serving as the predominant (e.g., Cm-Fm-G-Cm in the key of C minor)
• Variations of these progressions can be created by substituting chords with similar functions, such as using ii instead of IV or vi instead of I

Analyzing Chord Progressions

• To analyze a chord progression, first identify the key of the piece by looking at the key signature and the final chord (which is usually the tonic)
• Next, label each chord with its roman numeral based on its position within the scale (e.g., I, ii, iii, IV, V, vi, vii°)
• Identify the function of each chord (tonic, predominant, dominant) based on its roman numeral and the context of the progression
• Look for common chord progression patterns, such as I-IV-V-I or I-vi-ii-V-I
• Analyze any deviations from the expected progression, such as substitutions or borrowed chords, and consider their effect on the overall harmony
• Pay attention to cadences, which are the endings of phrases or sections, as they often involve specific chord progressions (e.g., V-I for an authentic cadence)

Applying Predominant Function

• When composing or arranging music, use predominant chords to create tension and lead towards the dominant and tonic chords
• In a typical chord progression, place the predominant chord(s) after the tonic and before the dominant
• Use ii and IV chords in succession to strengthen the predominant function and create a sense of forward motion
• In minor keys, use the iv chord as the primary predominant, with ii° and VI as alternatives for variety
• Experiment with different combinations of predominant chords to create unique harmonic progressions
• Use predominant chords to create smooth voice leading between the tonic and dominant chords, ensuring that common tones are maintained or that voices move by step
• Incorporate predominant chords in cadences to create stronger resolutions, such as ii-V-I (plagal cadence) or IV-V-I (imperfect authentic cadence)

Ear Training and Recognition

• Developing the ability to recognize chord progressions and predominant function by ear is crucial for musicians
• Practice identifying the quality of individual chords (major, minor, diminished, augmented) in isolation
• Listen for the characteristic sound of predominant chords, which create tension and a sense of "pulling" towards the dominant
• Practice recognizing common chord progressions, such as I-IV-V-I and I-vi-ii-V-I, in various musical examples
• Transcribe chord progressions from recordings, paying attention to the bass line and the overall harmonic movement
• Sing arpeggios of predominant chords (ii, IV, vi in major keys; ii°, iv, VI in minor keys) to internalize their sound and function
• Engage in call-and-response exercises with a partner or instructor, where one person plays a chord progression, and the other identifies the chords and their functions

Composing with Chord Progressions

• When composing music, start by choosing a key and establishing the tonic chord
• Create a basic chord progression using the tonic, predominant, and dominant functions as a foundation
• Experiment with different combinations of predominant chords to create variety and interest in your progressions
• Use common chord progressions, such as I-IV-V-I or I-vi-ii-V-I, as a starting point, and then modify them to suit your musical goals
• Incorporate secondary dominants to create additional tension and color in your progressions
• Use chord substitutions to add variety and sophistication to your progressions, such as replacing IV with ii or vi with iii
• Consider the relationship between melody and harmony, ensuring that the chord progression supports and enhances the melodic line
• Vary the rhythm and voicing of chords to create interest and movement in your compositions