Chord – Scale Confusion. Can anyone help?

Steady Eddie · #1 03-23-2010, 02:53 AM

Why are triad chords made up from the first, third and fifth notes of a scale? Yet the three most harmonious notes of a scale are the first, fourth and fifth?

This has been giving me sleepless nights and any illumination on the topic would be most welcome.

Cheers.

jtroska · #2 03-23-2010, 03:05 AM

Not sure of the actual science of it, but the forth just doesn't sound very good in there. I think it's because the 4th is too close to the 5th. Playing 1st 3rd and 5th is playing every other note of the diatonic scale.

Also, the third determines whether a chord is major or minor. Playing C F G together sounds ambiguous. Playing C Eb G makes a minor triad.

The 4th is considered to be a note that should be played with caution. When soloing, it's usually best to step on and off of it quickly without spending too much time on it. That's why it's omitted from the major pentatonic scale.

MalcolmAmos · #3 03-23-2010, 07:19 AM

All of the above. I have been told the 1-3-5-7 and then the b3 and or b7, if that is the case, plus the identifying modal note - #4 for Lydian b2 for Phrygian, etc - are the melodic notes to take into account.

I also have been told that the I IV V chord contain every note in the tonic scale, thus those three chords are all you really need to harmonize any melody line - if it stays in scale. I chalk this up as two rules of thumb, one for melody and another for harmony. The two are related in that the melody and the harmony to harmonize must share some of the same notes. That sharing of notes is what governs the music we play in the Western World.

I just accept that the old guys worked this out a long time ago and it's not necessary that I take on that project.

I understand your need to know why.

MonetBass · #4 03-23-2010, 07:32 AM

Let's not confuse chord notes and scale notes. The 1st, 3rd, and 5th of a chord may or may not be the 1st, 3rd, and 5th notes of the scale in the current key. For example, key of C:

C major scale -- C, D, E, F, G, A, B, C

Now, when you build a chord, the common notation is to call the root R or 1, then of course the 3rd and the 5th regardless of the note within the scale being used as the root of that chord or triad.
(Note: UPPER CASE = major chord, lower case = minor):

I -- C E G
ii -- D F A
iii -- E G B
IV -- F A C
V -- G B D
vi -- A C E
vii° -- B D F (the '°' signifies that the chord is diminished due to the tritone between the B and F)

I hope that doesn't confuse you.

Rick Robins · #5 03-23-2010, 07:52 AM

Quote:

Originally Posted by Steady Eddie

Why are triad chords made up from the first, third and fifth notes of a scale? Yet the three most harmonious notes of a scale are the first, fourth and fifth?

This has been giving me sleepless nights and any illumination on the topic would be most welcome.

Cheers.

I think you are confusing Chord Progressions with Chord Qualities.

The bottom of this link might help you understand leading tones

http://www.tsmp.org/theory/lias/pdf/quickfacts.pdf

MalcolmAmos · #6 03-23-2010, 08:49 AM

Quote:

Originally Posted by Rick Robins

http://www.tsmp.org/theory/lias/pdf/quickfacts.pdf

Now that is something worth having at your fingertips, needless to say I bookmarked it.

Thanks for posting this.

Minotauros · #7 03-23-2010, 09:21 AM

Quote:

Originally Posted by MalcolmAmos

I just accept that the old guys worked this out a long time ago and it's not necessary that I take on that project.

"He who breaks a thing to find out what it is, has left the path of wisdom." - Gandalf to Saruman. I just like the quote.

mambo4 · #8 03-23-2010, 01:54 PM

Quote:

Originally Posted by jtroska

Not sure of the actual science of it, but the forth just doesn't sound very good in there. .

i think that's pretty much it.

As for the 4th and 5th being "most harmonious" It doesn't mesh with the the overtone series idea that the closer you are to the fundamental in the overtone series, the more enharmonic you are.

the overtone series intervals are 8ve, 5th, 2nd 8ve, 2nd5th , M3, and upward...you don't get to the 4th for a while.

The Idea that the 4th is among the most harmonic is probably rooted in the fact that it's an inverted 5th.

Chris K · #9 03-23-2010, 03:07 PM

Quote:

Originally Posted by Steady Eddie

Why are triad chords made up from the first, third and fifth notes of a scale? Yet the three most harmonious notes of a scale are the first, fourth and fifth?

This has been giving me sleepless nights and any illumination on the topic would be most welcome.

Cheers.

The notion of harfmony evolved over the centuries. In the early Middle Ages, only octave and 5th were considered to be harmonious, as was the 4th, which is of course a reversed 5th.
So the way you hear is is very, very authentic from a historical point of view.

Octave, 4th and 5th are considered perfect consonants.
3rds and 6ths, either natural or flat, are considered imperfect consonants.
2nds and 7ths are dissonants.

See also:

http://en.wikipedia.org/wiki/Consonance_and_dissonance

And... pleasant dreams!

JimmyM · #10 03-24-2010, 09:10 AM

the 1st, 4th and 5th together as a chord DOES sound good in the right context. this is called a "suspended" chord and is used often. but the 3rd is what gives a chord its major or minor tonality.

anyway, i agree with the others. this system for music has been in place for a very long time with little or no change over centuries. if it didn't work, people wouldn't use it. don't try to reinvent the wheel.