Scale degree names

In the previous chapter, we numbered the seven notes of a scale with Roman numerals. Each of those degrees also has a name — a label musicians use to describe its function in the music.

You’ll see these names in theory books, lesson notes, and sometimes in liner notes. They are:

Degree	Roman	Name
1	I	Tonic
2	ii	Supertonic
3	iii	Mediant
4	IV	Subdominant
5	V	Dominant
6	vi	Submediant
7	vii°	Leading tone

The two that matter

Six of these names are reference material — useful when you read them, not worth memorizing on day one. Two are essential: the tonic and the dominant.

Tonic — the home note

The tonic is the note (and chord) that the music feels anchored to. When a song “ends,” the final note is almost always the tonic. It’s the gravitational center of a key.

In C Do major, the tonic is C Do . In G Sol major, the tonic is G Sol . The key takes its name from the tonic.

Dominant — the note that pulls home

The dominant is the fifth degree. It carries an enormous amount of musical tension — it sounds like it wants to resolve back to the tonic. This pull is the foundation of nearly all Western harmony.

If you’ve ever heard a song that holds on a chord just before the final chord — a moment of “almost home, not yet” — that holding chord is almost certainly the dominant. When it finally moves to the tonic, the music feels resolved.

The others, briefly

• Supertonic (ii) — sits one step above the tonic. Often used to lead into the dominant: ii – V – I is one of the most common progressions in jazz.
• Mediant (iii) — sits halfway between the tonic and dominant. Underused in most pop, more common in classical and Greek music.
• Subdominant (IV) — one step below the dominant. Heard in I – IV – V – I, the bedrock of folk, blues, and most rebetiko.
• Submediant (vi) — six steps up. Often used as a relative minor substitute for the tonic.
• Leading tone (vii°) — sits one half step below the tonic. Its name is literal: it leads back to home. The strongest leading tone gives a scale its harmonic minor flavor (a detail we’ll return to soon).

You don’t need to memorize this list. You just need to know that tonic = home and dominant = pull to home. The rest will come naturally as you encounter real music.

Recap

• Each scale degree has a name as well as a Roman numeral.
• The two essential ones are tonic (the home note, degree 1) and dominant (the pull-home note, degree 5).
• The progression I – V – I — tonic to dominant and back — is the most fundamental motion in Western harmony.