This topic is going to be updated periodically as my understanding improves. As of December 2015 this is what I think I know about chords.

At first I understood that a melody  could have a harmony. This was based on my experience singing four part choral works and hymns in church. There was usually an accompaniment of some sort on the piano or organ or even in an orchestra. These accompaniments were not necessarily part of the melody but acted as a rhythmic source and a movement from one chorus or verse to another. That is about where I have been for many a year.

In undertaking my study of jazz over the last 10 years by reading jazz theory books and analysis I found that I just was not understanding the basics of music theory.

At this point I understand harmony to be those notes which are directly related to the melody. There may be different harmonies for the same melody. You have probably heard someone change the harmony notes for Happy Birthday or for Twinkle Twinkle, for example. The make it sound major or minor or like a tango, etc. That was a big step for me to understand that someone might compose a melody and then add some harmony to it later.

As a guitar player in my teens and twenties, chords were the rhythmic and musical accompaniment to my singing. In my 45 years of playing trumpet in shows and bands chords were part of the composers sonic creation.

Now, in learning jazz recently chords have a function (in classical music as well) that I am starting to understand. In a major scale using tertiary harmony there are four basic types of chords. Major, Minor, Dominant, and Half Diminished (also Diminished but less frequently used.)  There are many other places to learn how this is all related to the major and minor scales so I will not repeat that here. The function of a chord is to either move towards another chord or to resolve in preparation for another sequence.

The movement from one chord to the next is what I want to describe. Some time ago as I was starting to try to understand this mystery I corresponded with someone who gave me two chord progressions, one for major and one for minor. Since then I have found a large amount of resource material discussing these ideas. Basically however the progressions go like the following:

This image is from the site MusicTheory.net which is well worth a visit. With this understanding that there is some sense in music and that in many compositions both classical, popular, jazz, and more that there are patterns which are often repeated or slightly varied, my mind opened up to understand more along the path towards “Learn the Tune” which so mystified me.

In many standards and jazz classics the 2 5 1 progression of Minor – Dominant – Tonic is used frequently. What a nice name for the most stable chord – Tonic – sounds rather soothing!

The challenging tune – for me at least – All the Things You Are has the pattern

6 2 5 1 4 in Bb followed by 5 1 1 in D Major.

6 2 5 1 4 in F followed by 2 5 1 1 in A Major

2 5 1 1 7 3 6 4 in A Major although the 3 and the 4 are altered as 3D and 4D#5

6 2 5 1 4 in Bb Major followed by some altered chords b7 3 #2o and finally

2 5 1 1 in Bb major

The root motion rocks back and forth in a pattern in this song down 4 up 3.

I am at odds with my current teacher in thinking that the first 5 1 1 pattern could also be considered as altered chords of the first key of Bb. That would make them 7D 3M 3M