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Posted by on Jun 10, 2013 in Just Intonation, The Lattice, The Notes, Tonal Gravity |

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Tonal music is music that has a particular key center, or home note. Not all music is tonal, but most is, worldwide.

The key note is at the center of the lattice of fifths and thirds. All other notes are generated from this one. I call it the 1. It’s also called the tonic. When we say a song is “in the key of A,” we mean that A is the tonic.

This isn’t any particular A. In the key of A, every one of the ten or so A’s within the range of human hearing is a tonic, or perhaps more accurately some octave of the tonic. The tonic itself is an abstract concept, of “A-ness.”  In concert pitch, A is defined as a vibration of 440 cycles per second (called Hertz, or Hz), and any octave of this, up or down, is also a tonic. Thanks to a remarkable (and handy) quirk of human perception, multiplying or dividing a pitch by 2 does not change its essential character. So 220Hz is also an A, as are 110, 55, 27.5 — and 880, 1760 and so on forever.

The tonic doesn’t even have to be one of the 12 equal-tempered notes — it can be halfway between A and A#, and it will still work just as well. The rest of the notes are simply calculated from that home note. The resulting music will be in tune with itself, and will sound fine, even though it has no relation to concert (A=440) tuning. In learning songs from old recordings, I’ve found that many are in between two official keys. The instruments are tuned to each other, but not to any outside reference. They sound great.

The tonic sounds like home. The great driver of tonal music is the sense of departure from, and return to, home.

Be Love, like many tonal songs, starts right off with the tonic. It makes a statement, with the very first note: “This is where home is.”

Again and again throughout the song, the music departs from home, creating tension, and then returns to it, relieving the tension. The following clip contains two such homecomings, at 0:07 and again right at the end.

Then, finally, the song ends with the tonic. Ahhhh. Journey complete, the lattice has been explored, and after many adventures Sam Gamgee is back in Hobbiton.

Not all songs begin and end on the tonic. If you want the song to sound resolved, finished, end it on the tonic. If you want it to sound unresolved, unfinished, end it on another note. It’s a powerful tool. Listen to the end of Cream’s Sunshine of Your Love.

Have you ever had the experience of the audience clapping at the wrong time, in the middle of a song? It’s embarrassing!

Usually it happens when you pause for dramatic effect, and the audience thinks you are finished. You can send a strong signal that the song is not over by pausing on a chord that is clearly not the tonic. Then, when you do want the audience to clap, give them a big tonic chord and they’ll know what to do.

Next: The Compass Points

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Posted by on May 10, 2013 in Consonance, The Lattice, The Notes | 0 comments

Intervals

An interval, in music, is the difference in pitch between two notes.

Here’s Wikipedia’s definition:

In music theory, an interval is the difference between two pitches. An interval may be described as horizontal, linear, or melodic if it refers to successively sounding tones, such as two adjacent pitches in a melody, and vertical or harmonic if it pertains to simultaneously sounding tones, such as in a chord.

These two usages are very different from each other. “Interval” is used to describe pitch differences in both melodic space, the world of pitch, and harmonic space, the world of harmony. I think that’s a bit unfortunate in the case of harmony, because what drives the quality of a harmonic interval is not the difference in pitch (up, down) so much as the ratio between the two frequencies. The same interval may look very different in one space than in the other. Many intervals that are very close in pitch are far apart harmonically, and many harmonically close intervals are far apart in pitch.

Take the perfect fifth, for example. Here are two ways to describe the interval of a fifth:

  1. A pitch distance of 7 half steps, and
  2. Multiplication by 3.

The first way is simpler for thinking about melody, and the second is simpler for thinking about harmony.

Multiplying by three is the smallest harmonic move you can make, except for unisons and octaves. In harmonic terms, it’s the Note Next Door. But in melodic space, seven half steps is a long jump. Bass singers are kind of heroic in that way.

The following video shows a perfect fifth, in both harmonic space (the lattice) and melodic space (the keyboard).

Another example is the major second. This interval is a compound of two fifths, so the original note is multiplied by 3 twice. The major second means multiplication by 9. Harmonically, this interval is bigger than the fifth.

But in the melodic realm, the notes come out only two half steps apart.

Here’s the split screen version of the major second:

The major second is close in the melody and distant in the harmony. Notice how the major second sounds more dissonant than the fifth?

The word “interval” is also used to describe two notes sounding at once. An interval is the simplest harmony. Three or more notes is a chord, or a collection.

One note, all by itself, doesn’t have much of a personality, besides the timbre or sound of the instrument it’s played on. Without harmonic context, one pitch sounds pretty much like another. Some are higher, some lower, but that’s about the only distinction.

When two notes are played together, they create something new. Intervals have personalities, and each one is different from the others.

I think of intervals as the atoms of harmony. Intervals can be combined into larger collections, or molecules with more complex properties. Intervals and chords look entirely different on the lattice than they do on the keyboard, and I find that the patterns they form deepen my understanding of harmony. The lattice gives a window into harmonic space.

Next: Be Love

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Posted by on Mar 12, 2013 in The Lattice, The Notes, Tonal Gravity | 2 comments

Cadences

A cadence is a chord progression that gives a sense of arrival or resolution.

One particular cadence, the V-I (or V7-I) is especially powerful. In classical music, a V-I cadence is practically mandatory at the end of a piece, and it is the biggest gun in the composer’s arsenal when changing keys, or modulating.

The following movie shows a I-V-I progression. It starts on the I to establish the tonic, then there’s tension, then resolution. The V-I cadence draws the ear back to the tonic chord.

Here’s a cadence that visits the V7 first:

To me it looks like the V chord tosses out a rope, lassos the tonic and pulls.

It’s interesting to look at the notes in light of tonal gravity. In yesterday’s post, I laid out two rules of gravity on the lattice:

  1. Movement away from the center creates tension; movement toward the center gives a sense of resolution.
  2. The closer you are to the center in your journey, the stronger the sensations of tension and resolution are. The field is stronger closer in, just like real gravity.

There are four notes in the V7 chord.

  • The 5 is as close as you can get to the 1 (in harmonic space), so it creates a lot of tension. It is an overtonal note — that is, it appears in the overtone series of the 1. Pluck a string tuned to the tonic frequency, and the 5 will tend to be strongly present in the timbre of the sound. The way I see it, the ear is always searching for home. Every note gives it two clues — which direction is home, and how far away is it? The 5 gives a very strong signal, pulling the ear toward the tonic: “Home is this way, and it’s close! Come on!”
  • P1060030The 2 reinforces this conclusion. It’s farther out, so the signal is weaker, but it is still in the harmonic series of the 1, and it’s pretty close in. The little detective in the ear gets another clue.
  • Same with the 7, although now the effect is weaker. In traditional theory, the 7 is called a leading tone, and it’s thought to pull melodically toward the 1 — a sort of gravity in melodic space. It “wants” to resolve a half step upward. I feel this too, and I think the harmonic pull reinforces it further.
  • Then there’s the 4, which is what makes it a seventh chord (the 4 is a minor seventh of the 5). This is a reciprocal note, that is, it’s generated by division rather than multiplication. Like the 5, it points directly at the 1, from point-blank range. Reciprocal energy is different from overtonal energy. To me, it feels as though reciprocal notes are pushing toward the tonic — the message feels more like “Home is that way, now go!”

For the detective in the ear, the 4 slam dunks the case. The only reasonable conclusion is that home is located in that empty space between the 4 and the 5 on the lattice. Any other interpretation is much weaker. Every note in the V7 chord is pointing strongly to the 1, and when the notes collapse inward to the I chord, the resolution is completely satisfying.

I’ve heard a charming story about Beethoven. Apparently the composer was depressed and wouldn’t get out of bed. A friend came by and played some music, ended on a dramatic V7 chord, and sat down to wait. Beethoven finally had to get out of bed and play the tonic chord. Tough love! Don’t know if the story is true, but it certainly could be. The V7 is strong medicine.

When this particular chord shape appears somewhere else on the lattice, it can point so hard to its own center that the ear believes the tonic has moved. It’s as though the gravity of the planets is so strong that it can move the sun.

Next: Intervals

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Posted by on Mar 6, 2013 in Just Intonation, The Lattice, The Notes | 0 comments

Rosetta Stone

Almost all Western music, including my own, lives in the world of tonal harmony. This means:

  • There can be, and usually are, multiple notes playing at the same time.
  • There is a key center, or tonic, around which the notes are arranged. The tonic doesn’t always sound — it’s an intangible presence, the home from which you leave on your harmonic journey, and to which you will hopefully return.

The multiple notes can have different functions:

  • Roots are the fundamental notes of chords. A G chord has its root on G. Roots are local centers that move the ear around the lattice as they change.
  • Harmonies flesh out the chord. In a G major chord, the harmony notes are B and D. They stake out more lattice territory and add definition to the chord. Is it a G major, minor, seventh? The harmonies establish this.
  • Melodies dance in the harmonic field set up by the tonic, roots and harmonies. They have more freedom than the others. Melodies travel fast and light, and though they can sing the same notes as the others, they can also travel farther afield, further embellishing the chord, or leading the ear toward the next chord in the progression, or lingering on the last one after it has changed.

All this action is happening in two musical spaces at once.

Piano-keyboard

Melodic space is the world of scales. It’s organized in order of pitch. The piano keyboard is a perfect representation of melodic space.

full lattice all-01

Harmonic space is the world of ratios. Multiply a note by a small whole number ratio, and you have moved a small distance in harmonic space. Multiply by large numbers, and you have moved a large distance. The lattice is a map of harmonic space.

The two worlds are not the same. Often, they are opposites. The perfect fifth is a small move harmonically but it’s a mile in the melody — bass singers have to jump all over the place in pitch. Small melodic moves tend to be big harmonic ones. A chromatic half step, the distance between the 3 and b3, is only 70 cents, less than the distance between neighboring keys on the piano. But on the lattice, it’s a long haul — down a third, down another third, and up a fifth.

Writing and arranging a song is sort of like designing (rather than solving) a crossword puzzle. There are two intersecting, independent universes, Up and Down. To design the puzzle, you work back and forth between the two, massaging them until they don’t conflict, and each one makes sense on its own.

All of the notes live in both harmonic and melodic space. They may have a foot in one more than the other — the roots tend to move small distances on the lattice, the melodies usually move small distances in pitch, and the harmonies tend to bridge the two, moving melodically while staking out the form of the music on the lattice. But every note moves in both spaces, all the time.

Rosetta_stone_(photo)A great advantage of the lattice is that it serves as a sort of Rosetta Stone, a bridge or translator between the two worlds.

The Rosetta Stone was carved in 196 BC and rediscovered in 1799. It immediately became famous because it repeats the same text three times, in three different languages. It was the key that allowed scholars to decipher Egyptian hieroglyphs.

The lattice bridges the two musical spaces by means of the patterns it presents to the eye.

When two or more notes are plotted on the lattice, they will form a particular visual pattern. Any time you see this pattern, no matter where on the lattice it is, the relationship between the notes of the pattern will be exactly the same, in both harmonic and melodic space.

3-01For example, this pattern shows an interval of a major third. The ratio of the frequencies of these two notes is 5/4 (or 5/2, or 5/1 — twos don’t count, they just shift the note by an octave). Any time you see two notes in this formation, no matter where they are, you know they have the following relationship to each other:

  • Harmonic space: When the notes are sounded simultaneously, they will have the characteristic sound of a pure major third.
  • Melodic space: When you move from one note to the other, you are traveling a distance of 386 cents, or about four semitones on the piano.

Getting familiar with these patterns, and learning to recognize them wherever they are, has made it easier for me to think in harmonic and melodic space at the same time, which makes writing and arranging music much easier.

Next: Tonal Gravity

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Posted by on Feb 28, 2013 in Just Intonation, The Lattice, The Notes | 0 comments

Commas

One of the beautiful qualities of the lattice is that the patterns repeat everywhere. Notes that are in the same relationship to each other on the lattice will always have the same difference in pitch, no matter how where you go. For example, a move of one space to the right will always be a move up a perfect fifth, or 702 cents, wherever it happens.

2-The pitch difference between the 2 and 2-, shown in the last post, is about 22 cents (actually 21.5). This is not a big enough difference to be a different scale degree. In the key of C, the 2 is a D. The 2- is also a D, but of a slightly different flavor.

No matter where you are on the lattice, dividing by 5, then multiplying by 3 four times (the distance between the 2- and 2) will result in a pitch difference of 22 cents. The ratio, octave reduced, is 81/80. This sort of small interval is called a comma.

Commas in general are little intervals that pop up again and again in just intonation. There are three or four of them that are important enough to have names. This one is called the syntonic comma, or comma of Didymus, or just plain “comma.” It has its own (very good, I think) Wikipedia article.

There are three such pairs in my home territory of the lattice, the part I currently feel comfortable roaming:

didymic pairsEach of the notes in the lower right portion is 22 cents sharp of its namesake in the upper left.

Mathieu calls these pairs of notes Didymic pairs, or comma siblings.

In my naming system, I use a minus sign to show that the note is a Didymic comma flat of its sibling, and a plus sign to show that it’s a Didymic comma sharp.

These siblings start to show how the lattice repeats (almost) as it expands. The almost-duplication goes out forever in all directions.

Next: Another Comma

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Posted by on Feb 26, 2013 in Just Intonation, The Lattice, The Notes | 0 comments

Another Major Second: The 10/9

When I started exploring the extended lattice beyond the central 12 notes, the first note that was really new to me was the 10/9 major second, also called the minor or lesser whole tone. Now I call it the 2-.
Other-major-2-latticeThe lattice extends forever in all directions. When you continue multiplying and dividing, generating new notes beyond the boundaries of the central zone, the notes start to repeat, but not quite. The notes in red, the 2 and the 2-, are very close in pitch. They are different flavors, if you will, of the interval of a major second, or whole tone — a distance of two half steps, two keys on the piano.

Even though they are so close in pitch (204 cents for the 2, 182 cents for the 2-, only 22 cents apart), the two major seconds are generated in different ways and have very different functions and characters.

The 2 is an entirely overtonal note, that is, generated by multiplying alone. Such notes can be found in the chord of nature, the harmonics of a vibrating string. The character of notes is somewhat subjective, but for me, overtonal notes have a stable, sort of upbeat or positive character, and even though the 2 is somewhat dissonant, it has a kind of peaceful sound, that shows up well in ninth chords. Its recipe is x3, x3, or x9, octave reduced to 9/8.

The 2- is a combination of reciprocal and overtonal energy. It’s farther from the center than the 2, and more dissonant. Its recipe is /3, /3, x5, or 5/9, which octave reduces (or expands, really) to 10/9. It is darker, bluesier perhaps, and functions differently in chord progressions.

These very similar ratios, 10/9 and 9/8, 182 and 204 cents, are in fact entirely different beasts. Equal temperament has obscured this difference over the years. In ET, both notes are played at the compromise pitch of 200 cents, but that does not change the functional difference. It is extremely useful when writing or arranging to know whether you are playing a 2 or a 2-.

I tried making a demo of how they sound, as with other notes, but I think that played by themselves, out of context, the 2 and 2- are hard to tell apart. To get the difference, I think you have to sing them against a drone (scroll down the linked page a bit and there’s a list of Indian drones to play around with, it’s really fun to improvise melodies over these) and feel them in your own body. Mathieu shows you how to sing the 10/9 note in Harmonic Experience.

The functional differences really show up when you’re designing chord progressions that make sense. A chord progression is a journey on the lattice, and if you’re roaming in western territory, that is, to the left of the center, you want to use the 2- in your chords and melodies, and if you’re in overtonal, eastern lands, to the right of center, the 2 is going to sound better. It’s a crucial distinction in just intonation. Not so much in ET, since the notes are tuned the same — but awareness of where you are on the lattice really helps when you’re writing ET chord progressions.

It’s an old puzzle. Why do some progressions feel “right,” and others “wrong”? Knowing the map of harmony, the lattice, helps a lot. Much more to come in later posts.

Next: Commas

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