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Hi Mike

Thanks for the welcome.

Mmmm. With your NZ sister-in-law, you know we might almost be family.

Softchrome is correct. The seventh chord as he describes it would be conclusive evidence of a major key.

In the absence of seventh chords however, the clue that is just as strong is the presence of I, IV, V chords together.

As in this case: D, G and A in the key of D, and A, D and E in the key of A.

If anyone needs a list of all these I, IV, V, chords you could download my One Page Quicky And Dirty Harmony Lesson that I put together for some of my guitar students.

Feel free to download from here:

http://www.guitarteacher.net.nz/download/First-Harmony-Q&D.pdf


You might be wondering Why would someone would want to exclude a seventh chord from a song fer crissakes, when it does such a great job defining a key?

Well, to answer that question let me invite you to consider chords and harmony from this angle.

>>Harmony is like a seven story house.<<

On the ground floor is the single note. Each note is usually a member of a scale. The impact of one note played after another is melodic.

On the second floor there are the two notes or the double stops: 2nds, 3rd, 4th, 5ths, 6ths through to 11, 12, 13ths etc. The primary impact of these double stops is melodic.

On the third floor there are three notes or triads. It is at this level that the *primary* impact is harmonic.

It doesn't matter whether you play a triad on 3 strings on a guitar or all six strings, a triad is a triad is a triad.

Triadic harmony is the easiest for people to hear. Triadic music makes the most money.

On the fourth floor are four part chords, namely, major 7ths, dominant 7ths, minor 7ths, minor 7ths b5's etc etc. The impact of four part chords is harmony.

By triadic standards this is dense harmony.

On the fifth floor are five part chords, for example: major 9ths, dominant 9ths, minor 9ths, minor 9ths b5's etc. The impact of five part chords is harmony.

On the sixth floor is six part chords, for example: dominant 11ths and +11's, minor 11ths, minor 11ths b5's etc. The impact of six part chords is harmony.

On the seventh floor is seven part chords, for example: dominant 13ths, b13th and +13's, minor 13ths, minor 13ths b5's etc. The impact of seven part chords is harmony.

Now think about each floor as being *home to different styles*.

All the pop styles live on the third floor: from worship music to country music, folk, rock, pop etc. They might hang out on different sides of the hallways on the floor but ***harmonically** they are the same folk. They base themselves heavily in triads.

On the fourth floor you get the pop end of Jazz, blues and reggae etc.

Occcasionally one of the triadicists will run up to the fourth floor to play a dominant 7 chord but that's all they go there for. The rest of the time they stay on the third floor.

On the fifth floor your get the funksters, James Brown et al and blues. This floor is also dominated by jazz players and arrangers. The triadic tenants *never* come to this floor.

on the sixth floor and seventh floors there are mostly jazzers left. The triadic tenants can't remember these floors.

There is a corresponding *rhythm* aspect to each of these floor too.

The basic principle is this: the more loaded the harmony, the less persistent the rhythm.

So triadic harmony, being the harmonically lightest level, can withstand the most persistent rhythm.

Here's how you can test that idea.

Just take a regular Chuck Berry straight 8ths rock rhythm, like Johnny B Goode rhythm part and apply it to a triad, say A major.

You could probably handle that rhythmn playing triad chords for a good set or so.

Now do playing 7th chords with a Chuck Berry Rhythm. How long could you handle listening to that?

Now do the same with 9th chords, 11th chords and 13th chords. It's hard work to listen to, right?

So the general arranging guideline is: the denser the harmony, the sparser the rhythm.

This is partly because the denser the harmony is, the more time the ear needs to hear and absorb the sound.

So to return to the question: why might someone want to exclude a seventh chord from a song?

Here's some possible reasons:

1. The writer wanted to just stay on the third floor and define keys using just triads in which case 1, IV, V chords are just perfect.

2. Maybe the writer wanted to highlight the dominant 7 chord by changing the rhythm slightly fron the rest of the song for the V chord rather than adding a fourth part to the chord (and having to adjust the rhythm)

3. Maybe the rhythm was great for triads but tough for four part chords.

4. The writer doesn't like 7ths chords

5. The writer doesn't know about 7th chords (which is probably mostly a blessing on the third floor).

Dick Grove introduced me to the house of Harmony years ago and the house has helped me out on many an occasion in many a context.

HTHU

Cheers

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Taura Eruera
www.melodywriters.com