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Posted By: ZeroZero The world where a fourth is a third.? - 01/23/13 10:07 PM
The way I have my cerebral cortex wired for the piano there are basically 2 things

1] Scale fragments. These include the whole scale - eg. perhaps a run at the end of a song

2] Chord fragments (inversions, voicings)


From these two bags of bits I fashion all my impro.

For a long time the 'standard' Alt chord (sometimes called C augmented, also writtne 'A+' has been thwarting a comprehensive pin down in my brain, but I am getting nearer figuring out why.

It's a peculiar beast, this post is helping my brain sort this out.

Of course there must be other ways of looking at this chord, but here is mine:

The conventional spelling for an augmented chord is root, major third, augmented fifth.

Let's think of it in a function or setting. Let's consider it at the end of a blues in F where plain old 'C7' would play the dominant role and 'C(7)alt' would be a dominant substution.

If one were to play a C7 alt as a chord, I think the usual thinking would include the root, major third, and the raised fifth (which I understand to represent the + bit of the chord symbol). Anyways that's what I am going with here.

The flat 7 remains the same in botha C7 and a C alt.

Now if one were to what is the most common scale used for this chord, my guess is that this would be the C 'Altered scale' (aka the super locrain scale, diminished whole tone scale).

Basically this is C 'major' with everything flattened except the root. (there are other ways of speeling this scale but I won't explore them for fdear of adding even more confusion. Some people think this scale has both a diminished and a raised fifth for example).


Let's write it out:


1st - C
2nd - Db
3rd - Eb
4th - Fb
5th note - Gb
6th - Ab
7th - Bb
8th C

Another way of finding this scale fingering is to think of it as a scale built on the Locrian mode of the melodic minor scale. This gives us the correct fingering, but sometimes not the correct function. What I mean here is that the altered scale can function as the Locrian (called superlocrian) of the melodic minor but it also functions elsewhere, in other contexts - particularlty as a chord sub for the dominant chord.

Note the presence of both E and Eb in this C scale

Some also say that it has both a diminished and a augmented fifth. It also has no perfect fifth.


Now looking at the chord the first note is the the Root - thats the easy bit. No controversy there.

Now the next note in a standard first inversion chord (major or minor) would be the 'third' least this is how I normally think.

Well, lets count it pout. The second is Db and the the third note is Eb - on other words a minor third in contrast to the major third used in a C+ voicing.

The next note of a typical major or minor chord (triad) is the fifth. This is Gb (in this spelling) which I frequentlly think of as the diminished fifth, again not present in the C+ (C aug) which raised 'fifth' which in this reckoning is actually the sixth note of the scale.

So my conclusion is this:

A C+ chord is Root, fourth and 6th note of the Altered scale
note of the Altered scale



What sounds Good?

Now, when I play this chord, I find I can get away with all sorts. I can even get away with imposing a perfect fifth (which would technically be G sandwiched between f# and Ab) and often this sound sonorous and firm. Try playing a straight dominant 7th chord andd see - it works IMO.

I find this to be an intriguing musical thought. To me I think this is because the fifth is sonorous over any chord - even when sandwiched between two notes a semitone down and a semitone up.


Rule: (my rule) where you can play a note you can probably get away with the fifth above.



Now, taking the alternative approach, can you play the actual root third and fifth of the Altered scale?

Well, this gives a 'minor diminished chord'!!! You don't hear them mentioned often!

But, to my ears this works too - maybe up an octave. Its true though, the lack of the 'flat sixth' make a difference
.

Thw role of the alt chord functioning as a dominant seventh is to add extra tension so breaking rules is OK

So, you see for this chord, (in my weird brain) thirds are really fourths and fifths are really sixths !!!! ???

It's a strange Alice in Wonderland world! The Altered reality of the Altered chord.
Posted By: raymb1 Re: The world where a fourth is a third.? - 01/23/13 11:34 PM
http://en.wikipedia.org/wiki/Altered_chord

Here's one explanation of the X alt chord. Later, Ray
Posted By: Mac Re: The world where a fourth is a third.? - 01/23/13 11:58 PM
Quote:


For a long time the 'standard' Alt chord (sometimes called C augmented, also writtne 'A+' has been thwarting a comprehensive pin down in my brain, but I am getting nearer figuring out why.




Stop right there, the ALT chord is kind of like a "your choice" situation.

ALT chord can contain the b5 OR the #5 in it, sometimes even the b9 or #9. The dom7 can be used as well in certain instances.

It is not always simply an Augmented chord, if that was the case, why have the ALT designation, you could simply go with Aug or X+ and be done with it.

If you open some BB songs with the ALT chord designated, and watch what the keyboards play or what the notation shows, you will soon find out what's going on here.

Use of the BB Scale Generator can also show you some ways to do scale work over the ALT chords in those songs.


--Mac
Posted By: yjoh Re: The world where a fourth is a third.? - 01/24/13 12:35 AM
The article Ray put up is really good and as Mac has pointed out the altered note could be a semitone up or down.

ZeroZero, C aug or C+ chord will only ever be spelt as C, E and G#. I understand your way of thinking of C+ is the root, fourth and fifth of the altered scale but it only sounds the same, enharmonic equivalents that's all.
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