Roman numeral notation consists of two parts:
- The Roman numeral itself, which tells you the root of the chord; and
- The figured bass (the numbers that occasionally appear to the right of the Roman numeral) that tell you the inversion of the chord (ie, the intervals above the lowest pitch).
Let's start with the Roman numeral, which tells you the root. Since your example is in C, this entire post will focus on C major.
Now, think through the C major scale:
C D E F G A B C. In music we often assign "scale degree numbers" to these pitches, so C is "scale-degree one" in C, D is "scale-degree two," ... and B is "scale-degree seven." (The next C is not "scale degree eight," but rather it returns to "scale degree one.")
The Roman numeral is thus the scale degree written in Roman numerals. This means that your chord progression of
vi6 ii V6 I is based on chords whose roots are scale degrees six, two, five, and one. Your chords are thus built on A, D, G, and C.
Important to know is that uppercase Roman numerals indicate a major chord while lowercase indicates minor. (If you ever see a lowercase with a circle next to it, that means diminished.) Thus now we know the chords are A minor, D minor, G major, and C major.
A C E
D F A
G B D
C E G
So, now let's talk about the
6 that shows up occasionally; as we said, we call this "figured bass." For triads, there are only three possibilities:
- No figured bass at all means the chord is in "root position." In other words, the root of the chord (ie, the Roman numeral number) is the lowest sounding pitch. (Occasionally you might see this written as
53.) So your
I chords are in root position.
6 indicates the chord is in "first inversion," meaning the pitch a third above the root is in the bass. So
vi6 should have the chordal third in the bass.
A is the root, which means
C is the chordal third, so your
vi6 chord will actually have
C in the bass. (A similar thought process will address the
64 means the chordal fifth is in the bass, putting the chord in "second inversion."
With this knowledge, then, your progression should be what I give below; the lowest pitch is always given on the left. The remaining two pitches can be in any order, but the order I've given is the smoothest "answer" to this progression:
C E A
D F A
B D G
C E G
(As an explanation of your error, you may have been counting half-steps. Thus your
ii6 is a minor chord built on the second half-step of the scale,
C#. Similarly, your
V6 is a major chord built on the fifth half-step of the scale,
E. But this doesn't explain your first chord, so maybe that wasn't what you did. Or perhaps you read the
vi as a
iv, which is actually a really common mistake!)