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Author Topic: Bards - Threas Theory with Therise - Built to Scale  (Read 406 times)


Bards - Threas Theory with Therise - Built to Scale
« on: June 17, 2011, 03:59:31 am »
*A note is left on the board*

My illusions are kept from me
Until I've had my reverie
And so, I must report with sorrow
Class will be upon the morrow.
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Re: Bards - Threas Theory with Therise - Built to Scale
« Reply #1 on: June 22, 2011, 03:41:11 am »
*As the class files in, they see their teacher drinking a tall glass of water, a pitcher with a metal club glimmering with a cold enchantment sitting nearby.  When a slate is dropped with a clatter, she visibly winces, and clears her throat*

A better group than the Church of Xeen
At throwing parties, I've never seen.
But be that statement as it may
I'm paying for those revels today.

*She pauses, and clears her throat*

You know of pitch, the shades of tone
And time notation, too, is known.
But other rules will come to light
To make things easier to write.

Most notably, the scale and key.
Now all of you just follow me...

- - - - - - -

*A familiar figure in sprayed-on red jeans and t-shirt walks slowly into the room.  She doesn't seem to notice that her Ilsare shirt is inside out, and her hair is a bit mussed*

Right.  Lesson!

So, we've covered pitches, we've covered duration.  Now we're going to start into which pitches go well together - and to do that, we're going to have to discuss key.

Now, the other day, we discussed why, in western music, there are twelve tones.  But when you're writing music, how do you know which of the twelve tones to choose?  Do you just go with what sounds good?

Well, yes and no.  Yes, if you have a tune in your head that sounds good, write it down!  But for most people, harmonies don't jump in with the melody - and a lot of the time, we need help with the tune itself!  And that is where we come into today's topic - that of key and scale.  And we'll start with scales - a series of notes that runs the gamut from a note to its duplicate an octave higher.

To start with, we'll take a brief diversion into history - the ancient greeks, in fact.  They already had a sense of how to subdivide an octave into twelve notes (Pythagoras actually had a lot to say on the subject), but they also had a four-stringed instrument called a lyre.  Something like a harp in construction, but distantly related to the lute or guitar.  And they had several methods of tuning the instrument.

Now, a brief diversion for terminology.  If one divides the octave into twelve pitches, the "distance" between two adjacent pitches is called a semitone.  The distance between two pitches with a pitch between them, then, is a tone.  Got it?  Alright, back to the Greeks.

The lyre was tuned such that the interval between its highest and lowest string was a perfect fourth - the third harmonic interval, or the inverse of the second.  So one method of tuning the lyre was called diatonic, because it contained two whole tones (hence dia-tonic) and a semitone.  This was known as a diatonic tetrachord ("tetra" meaning four, and "chord" meaning strings.  The greek were often literal-minded in that fashion.)  Medieval music theory, fond as they were of greek classicism, defined scales in terms of greek tetrachords, and so defined a series of "diatonic scales".

You may have heard the terms "major" and "minor" before.  Well, a major scale is constructed of tones and semitones in the following order:

Or, if we look at it another way:

Two diatonic tetrachords separated by a tone!  It sounds like this.

But the greeks were cleverer than that.  They figured that you could change your starting point and give the scale a completely different feel.  They called these different scales "modes", and gave them names depending on their starting point, or tonic. Major, the scale you just heard, sounded "truest" to them, so they called it the Ionian mode.  The others were:
  • Dorian: T-S-T-T-T-S-T
  • Phrygian: S-T-T-T-S-T-T
  • Lydian: T-T-T-S-T-T-S
  • Mixolydian: T-T-S-T-T-S-T
  • Aeolian: T-S-T-T-S-T-T
  • Locrian: S-T-T-S-T-T-T
(Hmmm... where have I heard those terms before?)  You can hear the modes, starting from the same note, here.

Over the years, two of the modes grew in prominence (though the others still see use, particularly in jazz - ask me after class if you want to talk about it) - Ionian, which we know as a major scale, and Aeolian, which came to be known as the natural minor.  This was to distinguish it from the harmonic and melodic minor scales.  In these scales, one or both of the final two notes in the scale are raised to more closely approximate the second tetrachord of the major scale.  In the harmonic minor, the seventh note is raised both when ascending or descending.  In the melodic minor, both the sixth and seventh note are raised when ascending (making its upper tetrachord functionally identical to the major scale), but return to their natural notes when descending.  (You can listen to the natural minor, harmonic minor, and melodic minor.)

Finally, one other important scale is perhaps the simplest - the chromatic scale.  This is simply a series of semitones from one note to another spanning an octave.  In an even-tempered system (if you want to know more about even-tempering, I may speak on it later, or you can ask me after class), these are identical intervals, and it sounds like this.  Essentially, you play every note in sequence through the octave.

So, I hear you saying, why is this important?  What's so useful about scales?  And the answer is simply that they provide a framework.  The specific intervals that make up a scale produce a certain timbre, a particular feel to a piece of music.  For example, this cheery little tune sounds entirely different when it's based in a minor key.

A scale also gives a piece of music a sense of unity.  The tonic, the note upon which the scale is based, becomes a point from which to start and to which to return.  Certain intervals above it (most notably the fourth or fifth note of the scale, but more about that later) become important as well.  If a piece of music is a story, the scale, in many ways, is the setting.

Because of this, musicians are exhorted by their teachers to practice scales on their instrument of choice.  This is not some rote, arduous task assigned by teachers because it is traditional, nor (as some students might suggest) is it because the teacher hates them.  If you can train your fingers, voice, or embouchure to find the notes that make up a particular scale, then jumping from note to note in that scale when playing a piece becomes second nature.  In other words, students, scales are like broccoli.  Arduous to get through, but they make you better!

*she yawns suddenly*

Alright.  We'll get to key next week - I'll have some fun mnemonics for you again!  Also, I'll see what I can do to get you some examples, in notation, of the scales I mentioned today.  For now, your teacher has... some stuff to sleep off.

- - - - -

*Today, Therise simply waves goodbye, without a poem, and wanders off to bed, clutching her head*