We reviewed the homework, which I managed to get completely correct.

All major scales have the same roman numerals because all major scales have the same intervals. The same applies to minor scales. Roman numerals are useful for analyzing chord progressions because it doesn’t care about the root note or scale you are in. You can use the same major roman numerals between all major scales and the same minor roman numerals between all minor scales.

The relative minor of a major scale has the same notes in its scale. You can find the relative minor by getting the minor third below the root note.

Major roman numeral triads:

Roman Numeral	Third Interval	Fifth Interval
I	major	major
ii	minor	major
iii	minor	major
IV	major	major
V	major	major
vi	minor	major
vii dim	minor	minor

Minor roman numeral triads:

Roman Numeral	Third Interval	Fifth Interval
i	minor	major
ii dim	minor	minor
III	major	major
iv	minor	major
v	minor	major
VI	major	major
VII	major	major

dim stands for diminished, which is a triad with two minor intervals. There are also augmented triads which have two major intervals, but those don’t usually appear in traditional western music theory.

Note that the minor roman numerals have the same interval combinations as their relative major scale and the only thing that is different is the name. For example, a i in A minor and the vi in C major are both minor triads as they both contain the notes ACE; the intervals of the third and fifth note in the triad are the same.

We’ll talk about cadences and chord extensions next time and I have no homework assignment.