Week 6 - Class One

This week we are starting a two week-long investigation of creating interesting audio soundscapes for artistic installations. As we've discussed, I'm often disappointed by the lack of interesting sound work done for art in general, and installation pieces are often the worst: unchanging drones that chase you out of a room faster than a blathering art critic.

In order to do this, we are going to have to dive into 'music theory' a bit more than we did earlier. Today, we are going to learn the basics behind chords - and manually create some chords using the tone generator in Adobe Audition.

Remember, during week 1, when we were talking about working with the notes in a scale? It turns out that chords - groupings of notes that sound 'right' together - are made up of combinations of scale tones. Here is a chart I've made that shows the chords available from the C Major Scale - and how you construct them out of scale tones:

You can see that the name of the chord comes from the first tone in the series, then each additional note is two scale steps higher. So, using our frequency chart from the first week:

...we can figure out how to construct them in Audition.

Now, you don't always have to do the chord in the order shown. You can create inversions, which allow you to determine which notes are highest and lowest in your chord. Here are the typical 'closed' inversions of a C Major chord:

We can incorporate more of the scale tones to make more complex chords. The most often used added chord is the '7th' tone, which just adds a fourth tone to each chord:

You can, of course, do inversions of seventh chords as well; this gives some fairly spooky sounding options when the '7th' tone is the lowest note in the chord.

Now, in putting together chord movement ideas, it doesn't make sense to use the actual chord names, because each 'key' will have different chords for each position. Instead, we 'virtualize' the discussion by giving each of the chords a roman numeral.

So now, when we talk about chord changes, we can use this sort of notation:

I - ii - V7 - I

to represent the following progression of chords in the key of C:

C major - D minor - G7 - C major

or the following progression of chords in the key of A:

A major - B minor - E7 - A major

In-class Assignment:

Create Audition tone files for notes in the F scale, then create the following chord progression:

I - IV - V - I

Create Audition tone files for notes in the Bb (A#) scale, then create the following chord progressino:

iii m7 - vi m7 - ii m7 - V7 - I

Mix down the two progressions to audio files, then turn in these two files.

Assignment Due for Wednesday:

Find and watch three (3) videos about musical chord theory. There are many different approaches - many of which are very complex. Find three that help you understand chord theory better than you do now...

Week 6 - Class Two

In this class we are going to work on 'pivots' - using common notes to connect chords. We will start working with pivots within a key (using chords that are all from a single scale), but will also look at moving from one key/scale to another using common tones or chords.

First, let's look at a simple pivot between two chords in the C Major scale: moving from the G (V) chord to the C (I) chord. This is the most common chordal move, and it represents that 'satisfaction' that makes for a great end to a musical phrase.

Looking at our C Major scale chart:

... we can see that the G chord is made up from the notes G, B and D. The C chord is created by combining C, E and G. As we saw in the last class, this movement is made more interesting by emphasizing the common note between them: the G note.

G Chord (V) C Chord (I)

Now we are going to start applying some rules of thumb. First rule:

If you are 'resolving' to the "I" chord (the C chord in this case), you will want to end up with the root note as the lowest tone.

So let's add octave notations to these chords, and invert the C chord to put the C note at the bottom:

G Chord (V) C Chord (I)
G4 E4
B4 G4
D3 C3

Next, we need to choose a location for the common (G) note. It doesn't matter where you put it (in the top row or the middle row) - each will have its own sound. I'm going to place it in the center row; I'll move around the notes, but not actually change anything about the notes:

G Chord (V) C Chord (I)
B4 E4
G4 G4
D3 C3

Finally, I'll want to change octaves to make things move smoothly. If you would build these chords, you would hear that the top 'voice', which goes from B4 to E4, actually crosses underneath the common G4 note (remember, the notes/octaves go from C to C), so we will want to boost the E note up to octave 5:

G Chord (V) C Chord (I)
B4 E5
G4 G4
D3 C3

This gives us another rule of thumb:

Try to avoid unnecessary (or unwanted) crossing of voice lines.

While we could spend a lot of time going over general rules of music theory, that isn't in our best interests. One of the things that we bring to the compositional table is an 'art' view of the soundscape. As such, it means that we need to listen to ideas and make choices rather than intellectualize the 'proper' way of composing a piece.

Now, let's look at the sounds of different octave groupings of notes. We are going to use the I-IV-V7-I chord progression, which is a slightly jazzier version of the rock chords (jazzier mainly because of that 7th chord). Here are the chords, with the last C chord inverted to put the C note at the bottom:

C Chord (I) F Chord (IV) G7 Chord (V7) C Chord (I)
C4 F4 B4 E4
E4 A4 D4 G4
G4 C4 F4 C4

So, we've already dealt with one rule of thumb: the last chord ends with its root note as the lowest voice. Here's another rule of thumb:

Unless you have a good reason to do otherwise, have the lowest voice at least an octave below the other notes.

To support this rule, let's drop the lowest voice by an octave:

C Chord (I) F Chord (IV) G7 Chord (V7) C Chord (I)
C4 F4 B4 E4
E4 A4 D4 G4
G3 C3 F3 C3

And now, another rule of thumb:

Unless you have a good reason to do otherwise, have the highest voices share a higher octave.

What this does is prevent the impression that the chords are hopping around - it gives the chord progression a 'composer-ly' sound. Let's move the top voice around to put everything in the fifth octave:

C Chord (I) F Chord (IV) G7 Chord (V7) C Chord (I)
C5 F5 G5 E5
E4 A4 D4 G4
G3 C3 F3 C3

In addition to placing the top voice high in our listening range, this also has the benefit of pulling some of the notes out of the 'cluster' that we had sitting in the 4th octave. In general, if you have more than two notes clustered in an octave, the chord will sound 'dense'; if you have one or (at most) two notes in each used octave, the chord will sound more 'open' and 'light'.

Finally, we are going to look for interesting motion in some of the voices. The rule of thumb for this is:

Look for the following interesting voice movements (in order): common tones, stepwise movement, repeating phrases, palindromic phrases.

In our case, by inverting some of the chords, we can get a nice stepwise movement in the lowest voice, and some common tones in the top and middle voces:

C Chord (I) F Chord (IV) G7 Chord (V7) C Chord (I)
C5 C5 G5 E5
E4 F4 F4 G4
G3 A3 B3 C3

This also, inadvertently, helps us deal with our final (for now) rule of thumb:

Unless you have a reason to do so, don't put the added 7th tone as the lowest note of a chord. This almost always sounds bad!

In this case, because of how we sketched in the G7 chord, we had the F note as the lowest tone. This is generally a bad idea, so by inverting the chord, we've moved it into the center voices.

Create the necessary notes, then create the chord change above! You can use the tones found in this file: 4SA-C1thru6.wav

Jumping the Shark - or Changing Keys

Sometimes, for even more variation in your composition, you need to make more drastic changes. Key changes can accomplish two things: they can change the 'height' of the musical phrase, and the transitions can shine a bright spotlight on specific points. This will be especially important when we start working with audio-for-video/film.

Performing a key change transition can be jarring or it can be smooth. A jarring transition is pretty easy: you just start putting in music with a new key! But making a smoother transition requires pivoting, just like the chord changes. Only, this time, your pivot has to be a little more savvy.

Let's look at a smooth transition from the key of C (based off the C Major Scale) to the key of F (based off the F Major Scale). I've charted both keys - and included some extra information about the 7th tone - so we can see how to make a transition:

To move from the key of C to the Key of F, we would want to look for chords that are the same between two keys. In this case, F Major and A Minor are both common between the two keys. Hence, we could use the following chord progression to perform the key change:

(Key of C) (Key of F)
C -> G -> F -> F -> C -> F

Transitions to keys with no common chords can be a little more problematic. Let's look at a change from the key of C to the key of Ab:

In this case, we don't have any chords in common. But some of the chords: like C Major vs. C Minor, are the same except for one note (in this case, E vs. Eb). So we could use this chord as a transition that will be a little jarring, but gives us a lot of common tones to pivot upon.

(Key of C) (Key of Ab)
F -> G -> C -> C mi -> F mi -> Ab

So, as you can see, there is a process in making key-to-key and chord-to-chord transitions. We will want to use these concepts to create informed musical choices in our soundscapes, and can use the charting process (document available via this link) to pull it together.

In-class Assignment

Working in 3-person teams, perform the following chord and key changes:

Team A:

(Key of C) (Key of D) (Key of G)
ii -> V -> (transition) -> (transition) -> I -> (transition) (transition) -> V -> I

Team B:

(Key of A) (Key of E) (Key of Ab)
iii -> IV -> (transition) -> (transition) -> V -> (transition) (transition) -> vii -> I

Team C:

(Key of Bb) (Key of F) (Key of G)
iii -> VI -> (transition) -> (transition) -> I -> (transition) (transition) -> IV -> I

Assignment Due on Monday

Create a musical phrase that lasts 90 seconds, and transitions between at least 7 chords over two keys. Don't overlap the transition points between chords - I'll want to hear discrete chords when I review these! Use the 'rules of thumb' to create smooth transitions, and make sure that you chart the key information in order to make sure you are creating appropriate content.