Cadences and Predominant Function

Cadences and Predominant Function: AP Music Theory Study Guide

Hello, maestros and music enthusiasts! Today, we're diving into the grand finale of musical phrases - cadences. Think of cadences as the little punctuation marks of music. They're like the period at the end of a sentence, or the exclamation point in "Eureka!" And let’s not ignore their dramatic cousins – the predominant functions that set the stage for cadences to do their thing. Strap in, because we're in for a harmonic adventure!

A cadence is like the finishing touch that wraps up a musical phrase. Imagine you're on a musical journey, and cadences are the picturesque destinations where you pause to admire the view. They bring a sense of closure, relief, or sometimes even suspense, keeping listeners on the edge of their seats.

There’s an entire family of cadences, each with its own personality:

• Perfect Authentic Cadence (PAC): The ultimate showstopper.
• Imperfect Authentic Cadence (IAC): A close second, still impressive.
• Plagal Cadence (PC): The serene and peaceful ending.
• Deceptive Cadence (DC): The surprise plot twist.
• Half Cadence (HC): The cliffhanger.
• Phrygian Half Cadence (PHC): The historical drama.

Authentic cadences are the big finish, the drop-the-mic moments of music theory. They involve a dominant function chord (V or viio) traveling to the tonic.

Perfect Authentic Cadence (PAC)

A Perfect Authentic Cadence requires:

1. A V chord leading into a tonic chord. Not even a seventh chord can crash this party!
2. Both chords must be in root position, sitting pretty.
3. The soprano must end on the tonic note.
4. The soprano's final move must be a step.

When these conditions are met, you get that solid, "We're done here," vibe – no loose ends.

Imperfect Authentic Cadence (IAC)

When a cadence doesn’t meet all the criteria for being "Perfect," it’s dubbed Imperfect Authentic Cadence. It’s like saying, “We’re sort of done, but maybe the party isn’t over yet.” The IAC is versatile and often heard in the middle of musical thoughts.

Plagal Cadences are known for their gentle IV (or sometimes ii6) to I progression. Thanks to their constant use in hymns (that final "Amen"), they have a calm, reassuring touch—like a musical hug.

To achieve a Perfect Plagal Cadence:

1. Use a IV chord to lead into the I chord. Putting a seventh in the mix is rare but allowed.
2. Both chords should be in root position.
3. The soprano must end on the tonic and keep the common tone with the bass.

While not as emphatic as the PAC, it's like a warm, contented sigh at the end of a piece.

A Half Cadence ends on the V chord, creating a sense of anticipation. It’s like ending a TV episode on a cliffhanger, making you say, “Wait, what happens next?”

The Phrygian Half Cadence is a special half cadence used in minor keys, featuring:

1. A iv6 chord moving to a V, exclusively in a minor key.
2. Soprano and bass moving in contrary motion by step.
3. Ending with both soprano and bass on the dominant degree.

It's the musical equivalent of a spooky, unresolved ending that leaves you craving more.

A Deceptive Cadence plays with your expectations, moving from the V chord to anything but the tonic (usually vi). It’s like expecting the hero to ride off into the sunset but instead ending up at a surprise party.

The common trope is V to vi, but more dramatic shifts like V to IV are also in the repertoire.

• Common Practice Period: Era from approximately 1650 to 1900 when these rules were the law of the land.
• Contrary Motion: When two voices move in opposite directions—musical balance at its best.
• Dominant Function Chord: A chord creating tension that resolves to the tonic.
• Inversion (First Inversion): Chords re-ordered so their third, rather than the root, is the lowest note.
• Leading Tone: The seventh note of the scale, which loves to resolve to the tonic.
• Picardy Third: That surprising happy ending in a minor piece when the final chord is major.
• Root Position: Chord with the root note as the lowest pitch.
• Soprano Voice: The highest voice range, often carrying the melody.
• Tonic: The home base note, where stability is found.
• Voice Leading: The smooth transition from one chord to another.

In conclusion, cadences and predominant functions are the spice of musical life, giving phrases their structure, emotion, and drama. From the solid resolution of a Perfect Authentic Cadence to the charming unpredictability of a Deceptive Cadence, these elements are crucial to mastering music theory. Understanding these will not only help you ace your AP Music Theory exam but will also make you the life of every musical party. 🎉

Now go forth and conquer those harmonic progressions with confidence, and maybe even throw in a plot twist or two, just for fun!