Pentatonic scale

Keiji*** · #1 10-17-2005, 09:54 PM

I am hacking my way through learning theory on my own (no time for a teacher), and I find that the more I play, and read, the more realizations I come too (music theory is really quite interesting!) However, I seem to generate more questions than answers. Luckily, I write them all in my log book. Anyways, my first question is:

What is the theory behind a pentatonic scale? I know the name implies that there are 5 tones but why 5 vs. say...the 7 tones in a major scale? On that note, why 7 tones in the major scale? I am assuming that there is a good reason for this (physics/waves?).

Thanks For you time,
Keiji

JimmyM · #2 10-17-2005, 10:52 PM

Penta is Latin for 5. That's why there's not 7 tones.

Let me be completely honest with you. People can give you theories why, but nobody really knows the answer to your question. Some things are just the way they are. Accept it or not. Those are your two choices. It's like algebra. When you accept the formulas for algebraic equations without trying to get into the whys and wherefores of them, it's a lot easier to put those formulas to use.

Greater minds than ours came up with the musical scales centuries ago, and it's about the only language that has remained relatively unchanged for centuries. There's a reason...it works and works well. So don't go confusing yourself looking into the reasons why it works. You're not going to come up with a better system, so my advice is just to go with it.

RhythmBassist01 · #3 10-17-2005, 11:21 PM

Most 5 tone scales originated in Asia. In early Antiquities, scales had as few as 4 tones.

I like the log book idea. I keep a scape book for the bit of knowledge that I find useful, and there's quite a bit of it.

westland · #4 10-18-2005, 12:32 AM

The pentatonic scale dates from the first scales developed by the Pythagoreans of around 6th century BC. The Pythagorians were geometers, so they were interested in music as a branch of math (which to them was geometry). They were experts at splitting strings. They developed the first musical theory, and it turns out that a pentatonic musical scale can be devised with the use of only the octave, fifth and fourth. It produces three intervals with ratio 9/8 and two larger intervals.

Now you can go to a diatonic scale with the Pythagorian string splitting. If a 9/8 (whole tone) interval is carved out of the larger ones, a smaller (semitone) interval is left: B-C and E-F. This creates a Pythagorean diatonic scale. If the semitone thus created is taken from the whole tone, a chromatic semitone of different size is left over. This leads to some of the difficulties of Pythagorean temperament. It's why later theorists developed equal temperament.

In the Middle Ages, the church outlawed pentatonic melodies along with major-minor (Ionian, Aeolian) and developed the church modal systems. These came back into use in the Renaissance.

Keiji*** · #5 10-18-2005, 07:16 AM

Thanks for the history of 5 tone scales including the pentatonic.

Quote:

Originally Posted by JimmyM

So don't go confusing yourself looking into the reasons why it works. You're not going to come up with a better system, so my advice is just to go with it.

*laughs* I am not trying to come up with a better system, I just like understanding where things come from. Sure this knowledge may not help me become a better musician, but it will satisfy my curiosity.

JohnBarr · #6 10-18-2005, 01:03 PM

An intelligent question and an informative reply.
Thank you both.

John

zesi · #7 10-18-2005, 01:28 PM

the good thing about the minor/major pentatonic scale is that you can play it over every minor/major chord. The 5 tones of the pentatonic scale exist in every mode of the major scale (well, except that 5th in locrian). I don't know if this makes any sense to you, since I don't know how much music theory you know..

but say you've got a song in C major with this chord progression: C - Dm - Am - F - G

for the bassline you can choose the notes from C Ionian, D Dorian, A Aeolian, F .. etc. but you can also forget about all this and just play major/minor pentatonic scales over every chord. You won't even have to know what key the song is in..

well.. I hope I'm right on this one

Sandman1278 · #8 10-18-2005, 02:10 PM

Quote:

Originally Posted by westland

The pentatonic scale dates from the first scales developed by the Pythagoreans of around 6th century BC. The Pythagorians were geometers, so they were interested in music as a branch of math (which to them was geometry). They were experts at splitting strings. They developed the first musical theory, and it turns out that a pentatonic musical scale can be devised with the use of only the octave, fifth and fourth. It produces three intervals with ratio 9/8 and two larger intervals.

Now you can go to a diatonic scale with the Pythagorian string splitting. If a 9/8 (whole tone) interval is carved out of the larger ones, a smaller (semitone) interval is left: B-C and E-F. This creates a Pythagorean diatonic scale. If the semitone thus created is taken from the whole tone, a chromatic semitone of different size is left over. This leads to some of the difficulties of Pythagorean temperament. It's why later theorists developed equal temperament.

In the Middle Ages, the church outlawed pentatonic melodies along with major-minor (Ionian, Aeolian) and developed the church modal systems. These came back into use in the Renaissance.

wow that is quite interesting, anyone have links with more history on teh development of music theory? (yes, I did a forum search)

Hookus · #9 10-18-2005, 04:50 PM

But remember, some intervals are better suited for passing tones, rather than lingering on them in the groove. Typically, the 2nd is not very good to linger on, but the 3rd, 5th, and octave are (assuming a minor or major chord). IIRC, the major pentatonic uses the root-2nd-3rd-5th-6th-octave, and the minor uses the root-flat 3rd-4th-fifth-flat 7th-and octave. Use 4th's and 2nd's primarily as passing notes, and try not to linger too long on the 6th and flat 7th.

My personal favorite is the pentatonic minor, with the added tone in between the 4th and fifth. I never seemed to like how the major pentatonic sounds, even over major chords. It always seemed to me like the intervals were too far apart.

westland · #10 10-18-2005, 06:22 PM

I'm just speculating, but I think that because the intervals of the pentatonic are so fundamental to music, that this somehow resonates with us psychologically, which is why so much folk music is pentatonic (really anywhere as far as I know). The medieaval church wanted people to pull away from the sensual and secular ... to get people to stop dancing and tapping feet. So arose the church modal system.

In jazz, the blues scale (pentatonic min 3, b7 + b5) arose out of folk banjo-string music with the b5 a 'bent' note sliding into the dominant; but the piano, with its tempered, enharmonic scale made it something else -- as noted in one of the posts, it seems to fit into a lot of different harmonies.

Note too that the Pythagorian pentatonic is basically minor ... if you think of building a scale only with 5ths and octaves, you go up a 5th for the 5th, down a 5th for the 4th, down another 5th for the b7, and down another 5th for the b3 (I think I've got this right)... so pentatonic with b3, b7 = minor pentatonic.

WillBuckingham · #11 10-18-2005, 09:53 PM

You can construct any scale using perfect intervals, right?
And the most rational five-note scale is really a major pentatonic, I think.

If we run through the circle of fifths the first thing that materializes are the notes a major pentatonic and then a lydian mode of C or a G major scale..

C, G, D, A, E, B, F# or C,D,E,F#,G,A,B

If we did this in F we would wind up with the 8 white keys on the piano. If we did it in Gb we'd wind up with the 5 black keys as our major pentatonic.

So the major pentatonic scale is a very rational extension of the perfect fifth (3:2 ratio) and the lydian mode (and by extension the major mode) is an extension of that. I don't think the modes were part of a conspiracy to undermine musicality, and look at the tradition that sprung out of the church modes (Western Music in general and harmony).

I think its important to remember that music isn't an artifially conceived art, we're just playing with concepts that are inherent in nature.

And, not to rant, but isnt this the first thing that new music student's should learn? The significance of the notes that we play and WHY we have 12 notes etc. etc.

JimmyM · #12 10-18-2005, 10:44 PM

Middle Eastern and Indian music uses way more than 12 tones. They use quarter tones too, mostly as passing notes since they all use western instruments nowadays.

There are lots of physics level reasons why you can attibute the evolution of the frequencies used, but the bottom line is that they sounded good and everyone agreed. Yeah, it's fun to know all the ins and outs of all that stuff, but I believe the notes came first and the explanations why they worked came later.

WillBuckingham · #13 10-18-2005, 11:03 PM

Well I was describing why these notes are what they are, and their place in nature, its simple physics. Chinese music uses 12-tone system, and that developed independantly of Western Music. My point was that our musical system is the result of natural phenomena. Obviously there are more than 12 possilbe frequencies, and we use them in western music and especially jazz music, as you and I both know, playing fretless instruments.

The ancient Greeks understood these intervals and connected them with the structure of the universe. I think they had a better understanding of the significance and importance of music than a lot of people do today. The birth of harmony occured because Medievel scholars read Aristotle and started singing chant in parallel fifths, so at least on some level the ratonale behind this stuff came before the practice.

westland · #14 10-19-2005, 12:06 AM

This actually got me thinking, so I updated my blog with a bit more complete history of what I know about the pentatonic

See My Blog

Red Wonder · #15 10-19-2005, 11:03 AM

Quote:

Originally Posted by zesi

for the bassline you can choose the notes from C Ionian, D Dorian, A Aeolian, F .. etc. but you can also forget about all this and just play major/minor pentatonic scales over every chord. You won't even have to know what key the song is in..

well.. I hope I'm right on this one

Yeah you're right...if you want to be like the million other hacks out there. For the rest of us we study theory and applications.

unatratnag · #16 10-19-2005, 02:56 PM

Quote:

Originally Posted by Red Wonder

Yeah you're right...if you want to be like the million other hacks out there. For the rest of us we study theory and applications.

1) that wasn't very nice
2) you don't necesarily need a lot of notes to express yourself musically and aren't a hack if you favor the pentatonic scale.

Hookus · #17 10-19-2005, 04:35 PM

I think you are missing his point. Niceties aside, if you want to chug roots or whatever, more power to ya, but understanding why what you are playing works rather than memorizing a fingering pattern is what makes a truly great musician, not some guy in a band.

westland · #18 10-19-2005, 05:29 PM

Quote:

Originally Posted by WillBuckingham

Well I was describing why these notes are what they are, and their place in nature, its simple physics. Chinese music uses 12-tone system, and that developed independantly of Western Music. My point was that our musical system is the result of natural phenomena. Obviously there are more than 12 possilbe frequencies, and we use them in western music and especially jazz music, as you and I both know, playing fretless instruments.

Perhaps more important is how they come up with these 12-tones. The Chinese are big on twelves (a mystical number), with 12 heavenly stems and branches, 12 animals in the zodiac, etc. Chinese music starts with the octave and divides it into twelve smaller units using ratios of 3:2 to generate rising fifths and 3:4 for falling fourths (this dates from the 7th century BC Book of the Master Guan). The Pythagoreans did the same thing about the same time, but used the ratios 2:1 and 3:1 as basic.

Both were great up to the pentatonic scale, but in trying to squeeze out the additional notes, they got nasty results. Gioseffo Zarlino during the Renaissance perhaps did the most to try to promote tuning spread the the dissonances out. This was needed as you got large ensembles, and there were more opportunities for 'blue notes'.

WillBuckingham · #19 10-19-2005, 09:47 PM

I haven't read Pythagoras, but . . .

a 2:1 ratio is an octave. 3:1 is an octave plus a fifth. 3:2 is a fifth, we're essentially splitting hairs here.

My point was that a 12-tone system arose independantly in two musical systems because it is the result of natural physical properties.

zesi · #20 10-20-2005, 12:24 AM

Of course you shouldn't be satisfied with just playing pentatonic scales all the time, but I think it's a good thing to start with. As a beginner you can't jump right to knowing / playing all the modes.

Besides, you can still sound like any other hack even if you're using every single note on the fretboard.