Supertonic

The supertonic is the second scale degree of a diatonic scale, sitting one whole step above the tonic. In AP Music Theory it matters twice, first as a scale-degree name (Unit 1) and then as the root of the ii chord, the workhorse predominant in functional harmony (Units 3 and 5).

What is the Supertonic?

The supertonic is scale degree 2. The name literally means "above the tonic," and that's exactly where it lives, one whole step up from the home pitch. In C major, the supertonic is D. The CED (PIT-1.E.1) lists it alongside the other scale degree names you need cold: tonic, supertonic, mediant, subdominant, dominant, submediant, subtonic, and leading tone.

The supertonic gets a second life in harmony. Build a triad on scale degree 2 and you get the supertonic chord, written ii in major keys (lowercase because it's minor) and ii° in minor keys (diminished, hence the ° symbol per PIT-2.A.1). That chord is one of the most common predominants in 18th-century style, meaning its main job is to set up the dominant. A huge share of the progressions you'll analyze and write boil down to some version of ii going to V going to I.

Why the Supertonic matters in AP Music Theory

The supertonic shows up at three separate checkpoints in the course. In Topic 1.4 (AP Music Theory 1.4.B), you have to identify a pitch's function relative to the tonic using scale degree names, so "supertonic" needs to be instant recall. In Topic 3.2 (AP Music Theory 3.2.A), you label the triad built on it with the correct Roman numeral and quality, ii in major and ii° in minor. Then in Unit 5, harmonic function questions (like AP Music Theory 5.2.A and 5.4.A) put the supertonic chord in context, where it sits in the predominant slot of the phrase model. If you only learn it as "the second note," you miss the payoff. The supertonic is how the course teaches you that a single scale degree can be a melodic label, a chord root, and a functional category all at once.

How the Supertonic connects across the course

Tonic (Unit 1)

Every scale degree name is defined by its distance from the tonic, and the supertonic is the simplest case. It's the note right above home. Melodically, scale degree 2 loves to resolve down to 1, which is why so many cadential melodies end 2-1.

Diatonic Chords and Roman Numerals (Unit 3)

The supertonic triad is a great quality-check test case. In major keys it's minor (ii), but in minor keys it's diminished (ii°). If you forget that switch, you'll mislabel chord quality on Roman numeral questions all day.

Subdominant and Predominant Function (Unit 5)

The ii chord and the IV chord share two common tones and the same job, pushing toward the dominant. Think of ii as IV's close cousin in the predominant family. Unit 5 also adds vi as a weaker predominant (PIT-2.J.1), so you end up with a whole predominant team feeding V.

Leading Tone (Unit 1)

Supertonic and leading tone are the two scale degrees hugging the tonic from opposite sides. Scale degree 2 sits a whole step above, scale degree 7 a half step below, and together they create the gravitational pull back to scale degree 1 that defines tonal music.

Is the Supertonic on the AP Music Theory exam?

Expect the supertonic in two flavors of multiple-choice question. Scale-degree questions ask you to name or locate scale degree 2 by ear or in notation (that's AP Music Theory 1.4.B territory). Harmony questions ask you to identify the ii or ii° chord from a Roman numeral, a notated chord, or a played progression, and to recognize its predominant role in progressions like ii-V-I. Practice questions also probe how the supertonic chord relates to neighbors like the mediant in harmonic progressions, so know the functional map, not just the labels. On the FRQs, the supertonic earns or loses you real points in part writing and figured bass. Voicing a ii or ii° chord correctly (doubling, quality in minor, smooth motion into V) is bread-and-butter scoring material even when the word "supertonic" never appears in the prompt.

The Supertonic vs Subtonic

These names sound like opposites because they are. The supertonic is a whole step ABOVE the tonic (scale degree 2), while the subtonic is a whole step BELOW the tonic (the lowered scale degree 7 in natural minor). Don't confuse the subtonic with the leading tone either; the leading tone is only a half step below the tonic. The prefixes do the work, super means above and sub means below.

Key things to remember about the Supertonic

• The supertonic is scale degree 2, located one whole step above the tonic (D in the key of C major).

• The chord built on the supertonic is minor in major keys (ii) and diminished in minor keys (ii°), and the Roman numeral case and symbol have to match that quality.

• The supertonic chord functions as a predominant, which means its most common move is to the dominant (V), making ii-V-I one of the foundational progressions in the course.

• The ii chord shares two common tones with IV and does the same predominant job, so treat them as interchangeable members of the predominant family.

• Melodically, scale degree 2 tends to resolve down by step to the tonic, which is why 2-1 endings are everywhere in tonal melodies.

• Don't mix up supertonic (whole step above tonic) with subtonic (whole step below tonic) or leading tone (half step below tonic).

Frequently asked questions about the Supertonic

What is the supertonic in music theory?

The supertonic is the second scale degree, one whole step above the tonic. In C major that's D, and the triad built on it is the ii chord, a common predominant that leads to the dominant.

Is the supertonic chord major or minor?

It depends on the key. In major keys the supertonic triad is minor, written ii. In minor keys it's diminished, written ii°, which is one of the most commonly missed quality changes on Roman numeral questions.

What's the difference between the supertonic and the subtonic?

The supertonic is a whole step above the tonic (scale degree 2), while the subtonic is a whole step below the tonic (lowered scale degree 7, found in natural minor). The prefixes tell you everything, super means above and sub means below.

Does the supertonic chord resolve to the tonic?

Not usually, no. In 18th-century style the supertonic chord almost always moves to the dominant (V) first, and the dominant then resolves to the tonic. Going ii straight to I is a progression you should avoid in AP part writing.

How is the ii chord different from the IV chord?

Both are predominants that lead to V, and they share two common tones (in C major, ii is D-F-A and IV is F-A-C). The ii chord often gives a slightly stronger push toward the dominant because of the root motion by fifth from ii to V, but on the exam you can treat them as functional siblings.