1. Mr. Jackson AP Music Theory
Unit 5 : Triads
Mr. Jackson
AP Music Theory

2. TRIADS
A TRIAD is a three-note chord (built like a snowman) made up of two intervals stacked in thirds.
Tertian Harmony – built on thirds!

3. TYPES OF TRIADS
There are four possible ways to combine major and minor 3rds to produce a tertian triad.

4. TYPES OF TRIADS
+ Major minor dim ()
(Augmented)
(Diminished)

5. TYPES OF TRIADS (SOUND)
Each triad has a different SOUND CHARACTERISTIC.
Sounds
Sounds
Sounds like
Sounds like
“Happy”
“Sad”
“Tied to Train Tracks”
“Jellyfish on Animal Planet”
Tritone, ‘Smaller’ sound
Augmented 5th, ‘Awkward’ sound

6. HOW TO BUILD A TRIAD
Build the “snowman” in thirds above the root. Tertian harmony thirds will either be all lines or all spaces!
Identify the quality of the lower third as major or minor.
Identify the quality of the fifth (between the root of the triad and the fifth) as perfect, diminished, or augmented.
You can also identify the quality of the upper third as major or minor (between the third of the triad and the fifth.)
Identify the chord with a letter (the root of the “snowman”.)
Identify the quality of the triad:
M3 + P5 = major triad (or M3 + m3)
m3 + P5 = minor triad (or m3 + M3)
m3 + dim5 = diminished triad (or m3 + m3)
M3 + Aug5 = augmented triad (or M3 + M3)

7. HOW TO BUILD A TRIAD
If you know what the major triad is, then you can easily adjust the third and the fifth to create the other chord qualities.
From major, raise the fifth to create an Augmented Triad.
From major, lower the third to create a Minor Triad.
From major, lower the third and the fifth to create a Diminished Triad, or
From MINOR, lower the fifth to create a Diminished Triad.

8. TRIAD STABILITY
A triad that is a combination of the strongest intervals is the most stable. The perfect fifth is by far the strongest interval, and this accounts for the superior stability of the major and minor triads.
Major Triad Strongest and most stable
Minor Triad Strong and quite stable
Diminished Triad Weak and unstable
Augmented Triad Weak and unstable

9. TRIAD NAMES
You can construct a triad on any of the scale degrees. The triad has the same function name as the individual pitch. Both the pitch C and the C major triad are the tonic in the following figure.

10. TRIAD POSITION
Triad Position identifies the note of the chord that appears as the lowest-sounding pitch of the harmony. Any of the three notes of the triad can appear as the lowest-sounding pitch.
ROOT POSITION – No matter what the arrangement of the third and fifth factors, the triad is in root position if the root of the triad is the lowest-sounding pitch. All of the triads below are in root position.

11. TRIAD POSITION
Triad Inversion occurs when the root is NOT the lowest-sounding pitch.
FIRST INVERSION – Occurs when the third of the triad is the lowest-sounding pitch, regardless of the arrangement of pitches.
SECOND INVERSION – Occurs when the fifth of the triad is the lowest-sounding pitch, regardless of the arrangement of pitches.

12. TRIAD INVERSION SUMMARY
FOOD FOR THOUGHT: Can you describe the difference between the BASS and the ROOT?

13. HEARING TRIAD INVERSION
“Stable Sound”
Hear the “Mi-Re-Do” Pull
Hear the “Sol Do” Pull

14. IDENTIFYING TRIADS IN MUSIC
The ability to recognize triads in music is critical to Score Analysis.
What triads do you see?
Keep in mind that triads may not always “line up” as they do in the Red Box.
They may be arpeggiated (as displayed in the blue circle).
They may also be staggered (as displayed in the green circle).

15. IDENTIFYING TRIADS IN MUSIC
Triads can also appear OUT OF ORDER in music as well. However, this is still an instance of an A Major Triad in Root Position.

16. Introduction to Part Writing
When studying harmony, we often will see a four-voiced texture called chorale style. Two goals define this style:
INDEPENDENCE OF VOICES &
DEFINITION OF TONALITY
Voice leading controls the relationship between voices.
There are rules concerning doubling and chord voicing.
* What’s the point? The point is – you may see TRIADS presented in a chorale style format! Be ready!

17. Part-Writing Voices/Ranges
When constructing chords vertically for part writing, we use four voices.
The name and ranges of these voices are derived from the four standardized singing ranges
SOPRANO
ALTO
TENOR
BASS
SOPRANOS/ALTOS are placed on the TREBLE CLEF of athe grand staff
TENORS/BASSES are placed on the BASS CLEF of the grand staff
We will discuss PART WRITING in much more detail later…