Monday, November 5, 2012

Musical Form, Part 2

Yesterday I put up a post about musical form that mostly talked about how melody can be used to structure a piece. This merely scratched the surface, of course as there are many, many ways that I didn't mention such as the way a melody can be transformed in the course of a piece so that it not only provides a unifying element, but also helps to push the piece forward. The 19th century particularly explored this idea.

But I'm not going to talk about melody today, instead, I'm going to merely scratch the surface of how harmony is used in musical form. Everyone knows what you mean when you use the word melody but harmony is a word with complex meanings. Like 'melody', it comes from the ancient Greek: ἁρμονία (harmonía) which meant joining or fitting together. We use it in a very general way to mean the vertical aspect of music: everything relating to notes sounding together. But there are more specific meanings as well. If you take a course in university in the music department called "harmony" it is going to be about the system of tonal 'grammar' that was used in Western music between 1600 and 1900. This system looked at different chords as being functional, i.e. they were part of a web of tension and release that was used to structure the flow of music. For example, a lot of recent music is based on drones, long-held notes and chords, and for that reason is not 'harmony' in the strict sense as there is no harmonic function. Here is a recent song by Paul Simon that is almost completely without harmonic function. The verses are all one unchanging riff and, therefore, harmony. The contrasting chorus mainly contrasts by dropping the riff and there is a hint, no more, of a harmonic change. But it is minimal. A theorist would say that moving to neighboring harmonies and then back is actually just extending the tonic.

To see how harmony works you could do no better than to look at some music by J. S. Bach who is admired as being probably the greatest master of harmony. Here is a very simple piece by him, the first minuet from the Partita No. 3 for solo violin. Just click to enlarge.

This piece is in E major, which means, in terms of functional harmony, that it is going to begin with an E major harmony and end with one. Later on Beethoven created quite a stir when he began pieces with something other than the tonic--usually the dominant. Ah yes, 'tonic'. The tonic chord or harmony is the one built on the key note, in this case E. By "built on" I am referring to how chords are constructed. You build a chord by taking every other note in the scale. For example, the E major scale goes E, F#, G#, A, B, C#, D# and E. A tonic harmony, starting with E, would be E, G# and B. Every other note. Simple. Here is the E major scale and three important harmonies derived from it: the tonic, on the keynote, the subdominant, on the 4th note, A, and the dominant, on the 5th note, B:
The basic layout of this minuet and virtually every other dance movement from the Baroque era is Tonic -- Dominant -- Tonic. But there are thousands of ways of going from tonic to dominant and back! One more thing before we go to the piece: as you will realize if you look back at that scale, you can build a chord on every note of the scale. The three chords I picked out and labelled, tonic, subdominant and dominant, are the main members of little families of chords. I say that because every chord has related chords that it shares notes with. The closest relationship is when two notes are shared. For example, the tonic, E, G# and B, shares two notes with the mediant: G#, B and D#. These two chords are related. Similarly, the subdominant, A, C# and E, shares two notes with the submediant, C#, E and G#. Mediant and submediant are labels for other notes of the scale. You want the whole list? OK:

  1. tonic
  2. supertonic
  3. mediant
  4. subdominant
  5. dominant
  6. submediant
  7. leading tone
All right, now let's look at the beginning of the minuet. Click to enlarge:

The first two measures are just as Bach wrote them. The next two are my simplification of the first two showing just the harmonies. It starts with the tonic, of course, and the next chord is the dominant. Actually, just part of the dominant, without the lowest note. Then we get that lowest note, B, but over it is a G# so what that harmony actually is, is the mediant. Then the next measure is the submediant. Yes, lots of stuff in just a couple of measures. I won't go through every measure because I just want to give you a taste of how harmony works. But to round things off, let's look at the ending. Click to enlarge:
The supertonic is part of the subdominant 'family' as it shares two notes and the mediant is part of the tonic 'family'. So the basic harmony of the last two measures is subdominant, tonic, dominant, tonic. Bach uses other family members to make it more interesting and smooth the movement of the voices. Now let's listen to the whole piece. Here is Arthur Grumiaux playing both minuets (they usually come in pairs).

The minuet we have been looking at is less than a minute of music without the repeats! But in that minute Bach has a wide range of harmonies, all carefully calibrated to move us toward the dominant, which is where the first half ends, and then move us back to the tonic. This is one way of using harmony to structure musical form. From about 1600 to 1900, this was the predominant way of putting a piece of music together.

No comments: