The iii (III) Chord: AP Music Theory Study Guide
Introduction
Hello, future maestros and chord architects! 🎶 Ready to dive into the mysterious world of the iii (III) chord? This little rascal loves to play hide and seek in chord progressions, sometimes sneaking in as a tonic prolongation or pretending to be a dominant chord. Grab your sheet music and sharpen your pencils—let’s decode the iii (III) chord's secrets!
Meet the Mediants 🎵
Let's get acquainted with our harmonic family. Each scale degree has a fancy name: Tonic, Supertonic, Mediant, Subdominant, Dominant, Submediant, and Leading Tone. This is like the "Royal Family of Notes," and the Mediant is the third degree, chilling right between the Tonic and the Subdominant. Think of it as the middle child trying to find its place—sometimes it's a superhero, and sometimes it just wants to blend in.
In major keys, the iii chord (also written as III in minor keys) can serve a couple of roles. It might act as a slightly out-of-breath predominant or shake things up as a tonic prolongation. Ready to explore? Let's march on to see the iii chord in action!
The Mediant as a Weak Predominant
When the iii chord tries to be a predominant, it's kind of like that awkward moment at a party where you wonder if you should dance. If the iii appears before stronger predominant chords like IV or ii, you get progressions like I-iii-IV, which is delightful and common. But remember, iii’s predominant party trick is never as strong as its buddies, like the mighty subdominant IV or ii chord.
If you're feeling fancy and using both iii and vi chords, the iii almost always precedes the vi since it's the weaker of the two. Picture it like a prince bowing to the queen in a musical hierarchy.
The Mediant as a Dominant Deceiver
Sometimes the iii chord has a little identity crisis and tries on the dominant hat. If you see a iii6-V progression, don't rub your eyes; you’re not imagining it. The iii chord is masquerading as a dominant with its fellow traveler, the non-chord tone. In first inversion, the iii chord sneakily contains scale degrees that make it sound like a dominant chord but with an extra, non-chord flavor.
In minor keys, you might stumble upon the curious III+ chord. Here, the iii chord pretends to go rogue, but really, it's just borrowing notes from the dominant. This chord progression reminds us that, sometimes, even chords can wear masks.
Expanding the Tonic With the Mediant
For a tonic expansion with pizzazz, try a I-iii-I, or if the bass line wants to steal the show, a I-iii-I6. You can also spice things up by sliding in a non-functional IV chord after the iii, like putting sprinkles on a harmonic cupcake. Just remember, this IV is here for flair, not to hog all the harmonic spotlight.
A typical tonic expansion progression is I-iii-IV-I, which lets your melody step gracefully downward. Imagine a singer stepping down a staircase, hitting each note confidently, making the phrase feel naturally connected and flowing.
Polly’s Progress Tracker 🦜
Polly gets an extra tweet if you craft a harmonic progression using every diatonic chord! Try to make a Tonic–Predominant–Dominant–Tonic phrase (T-PD-D-T). And remember, rules might seem strict, but they’re just guidelines for happy harmonic surprises.
The Mediant in Minor Keys: Tonicization and Modulation
In minor keys, the III chord is like a gateway to the relative major. Think of b minor sliding into D Major, its sunny-side-up relative. Composers love to use this trick to keep listeners guessing. Short visits to other keys are tonicizations; longer stays are modulations.
If, while analyzing, you spot an invasion of III, VII, and VI chords, you might be snooping around a modulation to the relative major. For example, in d minor, frequent appearances of C naturals could signal F Major territory. Welcome to harmonic espionage! 🕵️♂️
Key Terms to Know
- Diatonic Chords: These are the loyal chords of a key, sticking to the notes within the scale like musical glue.
- Dominant: The bossy fifth degree, always leading back to the tonic.
- Harmonic Functions: Each chord has its job, like a team: Tonic is the base, Dominant craves tension, and Subdominant loves contrasts.
- Modulation: Changing keys, like moving to a new musical neighborhood.
- Roman Numerals: Our secret code to crack the harmonic enigma within a key.
Fun Fact
Did you know the iii chord is like the Clark Kent of harmonies, often overshadowed but crucial to the story? 🦸♂️
Conclusion
There you have it, music magicians! The iii (III) chord might be the underdog, but it's full of surprises. Whether prolonging the tonic or stepping in as a weak predominant, it adds a special spice to musical progressions. So next time it appears in your sheet music, nod in appreciation and let its subtle charm enhance your masterpiece. Happy composing! 🎼
