Theory On Tap Lesson 7, Pentatonic Scales and the Blues by: Greg Brouelette While many people think of pentatonic scales as nothing more than a trick to use when playing the blues, I think you'll find these simple five tone scales have a broad range of feelings and styles.
	The prefix `Penta' means five. So a pentatonic scale is a five tone scale. When we think of pentatonics most people think of the blues scale, but you can build a pentatonic scale out of ANY five scale tone you want. Mathematically this is shown as "12 choose 5". Which is:
	12! ------------- = 792 5! ( 12 - 5)!
	Which gives us 792 pentatonic scales and each of them can be played in any key so there are actually 9504 scales , although not all of them sound good. So the next time someone tells you pentatonics are too limited, slap them. (Or better yet, ask them to name them all).
	We're going to concentrate on just a few of these scales. Probably the most popular pentatonic scale is the blues scale. Before I show you this scale we must learn to play the blues. "The 12 Bar Blues" chord changes are based on a I-IV-V chord sequence. Notice how the entire chord sequence uses only these three chords:
	C F C C | / / / / | / / / / | / / / / | / / / / | F F C C | / / / / | / / / / | / / / / | / / / / | G F C C | / / / / | / / / / | / / / / | / / / / |
	In the key of C, the `I' scale tone is C, the `IV' scale tone is F, and the `V' scale tone is G.
	You'll notice that I'm refering to scale tones rather than the I chord, the V chord or the IV chord. If you remember from my mode lesson, the I and IV should be major 7th chords, and the V is a dominant 7th chord. But if you play it this way it sounds like . . . . well . . . .It certainly isn't the blues. We usually just play dominant 7th chords for each (or anything based on a 7th, like a 9th, 11th or 13th chord).
	OK, what about the blues scale? The blues pentatonic uses the following notes of the I scale: Root, m3, 4, 5, b7. Wait a minute! We're playing a 7th chord which has a Major 3rd in it and our scale has a minor 3rd! How can this sound good? Well, that's what gives it the bluesy sound we're so use to. On the Stick this scale looks like this:
	|-----|-----|--X--|-----|--X--|-----|--X--| |-----|-----|--X--|-----|--R--|-----|-----| |--X--|-----|--X--|-----|--X--|-----|-----| |--X--|-----|--R--|-----|-----|-----|-----| |--X--|-----|--X--|-----|-----|-----|-----|
	Of course, this is just one way to play it. You can invert some of the notes and get this fingering:
	|-----|-----|--X--|-----|--X--|-----|--X--| |-----|-----|--X--|-----|--R--|-----|-----| |-----|-----|--X--|-----|--X--|-----|-----| |-----|-----|--R--|-----|-----|--X--|-----| |-----|-----|--X--|-----|-----|--X--|-----|
	Usually, the fingering is just the first and third fingers which allows us to move really fast. We can also use a bending technique to give it a bluesier feeling. Any of the notes can be bent but traditionally we bend like this:
	|-----|-----|--X--|-----|--B--|-----| |-----|-----|--B--|-----|--R--|-----| |-----|-----|--B--|-----|--X--|-----| |-----|-----|--R--|-----|-----|--X--| |-----|-----|--X--|-----|-----|--X--| Where B = Bend the note
	I should mention that a blues player generally stays in the same scale regardless of where they are in the chord progression. So if we're playing in the key of C we find the C blues scale and set up house for the whole song. After a while this could get a bit tedious so we need some tricks to open up our sound.
	You might have noticed how easily the dorian scale fits on top of this pentatonic scale. This is a good way to `jazz up' your solo and break out of the old blues cliches.
	|-----|--X--|--X--|-----|--X--|-----| |-----|--X--|--X--|-----|--R--|-----| |-----|-----|--X--|-----|--X--|-----| |-----|-----|--R--|-----|--X--|--X--| |-----|-----|--X--|-----|--X--|--X--|
	Another good trick is to switch between a mixolydian and the blues pentatonic. You can play the mixolydian mode of whatever chord you're on, and then switch to the blues pentatonic in whatever key you're in. Remember, you're moving the mixolydian, but not the pentatonic. It's no wonder the blues pentatonic scale is so popular. You just find your home position and jam until they turn out the lights and lock the doors.
	Of course, you can follow the chord structure with your pentatonic as well. Just follow the I-IV-V movement of the blues progression with the root tone of the scale. There's a lot of ground to cover with that little 5 note scale.
	There is an excelent source for music theory at Marc Sabatellas "A Jazz Improvisation Primer" web page at http://www.acns.nwu.edu/jazz/ms-primer/ I'd like to finish the lesson with a few thoughts from an article by Ed Price on alternative pentatonics from that web site :

"Other five note scales are used occasionally as well. For instance, the scale "E, F, A, B, D" is the traditional Japanese "in sen scale". It can be used as a substitute for the E phrygian mode (note it in fact defines the E phrygian chord) to impart an Asian flavor to the music. Useful variations of this scale include the second mode, "F, A, B, D, E", which can be used over a Fmaj7#11 chord; the fourth mode, "B, D, E, F, A", which can be used over a Bm7b5 chord; and the fifth mode, "D, E, F, A, B", which can be used over a Dm6 chord.

"Since there are relatively few notes in a pentatonic scale, one pentatonic scale can often be used over several different chords with no real avoid notes. For instance, the C major pentatonic scale "C, D, E, G, A" could be used over Cmaj7, C7, D7sus, Dm7, Em7b6, Fmaj7, G7sus, Gm7, or Am7."

	Thanks Ed.
	As you can see, there's a lot of fun in that simple five note scale. And you can get a lot of blues, and a lot of sound from a very simple technique. Have fun with it! Greg Brouelette

The quoted material within is also copyrighted via the GNU system by Ed Price.