Chord Labelling with Roman Numerals

Techniques and Analysis 1 – Lecture 6: Chord Labelling with Roman Numerals

We’ve, of course, already been using Roman Numeral analysis to describe chords a certain amount during earlier lectures. Today I wanted to look at this in more detail, and clarify some specific principles and to develop a method for using it to look at more substantial stretches of music.

Most simply, the point of Roman Numerals is to indicate the FUNCTION of a chord in relation to the tonic. This goes back to that whole issue of relational language that I raised a few weeks ago - a chord is not inherently V, or vi, it is that relative to something else. This is the opposite of either figured bass or jazz chords, which are fixed notational systems, where one is being told what to play, not how that relates to the harmony around it.

So, in order to do this we ‘only’ need to know 2 things – what the chord is and what the tonic is. This, is, unsurprisingly, sometimes more complicated than it sounds! Let’s start off with some very simple diatonic music (this is a slightly altered version of the example from the style guide I’ve given you):

[pic 1]

Adapted from J.S. Bach French Suite No.4 BWV 809, iv, Sarabande

The only moment that doesn’t get given a function here is the 2nd quaver of bar 1 – this is really a neighbouring decoration, rather as we’ve just seen how to do in 3rd Species counterpoint. Otherwise, every verticality is described by the relation of its root to the tonic- note the collection of V7 chords in various inversions in bars 2 and 3. This takes us to the first point about the procedure for labelling used here that may differ from what you’ve learnt before – inversions are indicated using figuring rather than letters. So, hopefully just as a little reminder:

Numbers in brackets are implied in the figuring and don’t need to be written out.

Now, where things get more complicated is when it is harder to work out what the chord is or what the tonic is. We’ve actually already covered all the main concepts we need to analyze almost any tonal music in this way – between last week’s non-diatonic chords and modulations and our previous look at diatonic functionality there isn’t much else! But of course it is never actually quite that simple. Here is the full example from the style guide:

[pic 2]

There are a number of features to note here:

 1:  Bar 1-2 is a tonicization of IV – the Eb makes the second chord the dominant 7th of Bb, which is of course IV, but we then leave that for the bigger I-IV-V-I progression.

2: Although it contains the ‘notes’ of a tonic chord, the 64 in bar 7 is written as V. This is because the cadential 2nd inversion chord functions as the dominant – the E and C must resolve to D and B.

3: This is an obviously modulating example – it ends with a perfect cadence in the dominant. Here, I’ve indicated the modulation directly where the first harmony tonicizing C occurs. After the viio chord on the second beat of bar 5, the chords only really make sense viewed in relation to C. However, if the piece began in bar 5, this progression would make perfectly good sense as IV – V –I. So we could also view the chord on the downbeat of bar 5 as a pivot – one which has function in both the old and new keys.  If we choose this analysis instead, it would be notated as follows:

[pic 3]

The next page is a really detailed analysis of the complete Sarabande, which tries to account for every note, either as part of the chord that’s labeled, or as a decoration (passing/neighbor notes etc.). There are a few places where I provide alternate analyses (especially the circle of fifths), as either solution seemed acceptable to me.

Let’s now look at how to do this in some music where the texture is less obviously chordal. Here’s the beginning of a Haydn Piano Sonata we started looking at last week.