As expected, your course has lead me down the road to a greater understanding of music theory and the inter-relationship between roots and fifths. Can you take a moment to explain the chart showing this relationship? I have be able to understand most of it on my own, but I wanted to hear you explain it so that I am not misinterpreting what I am trying to work out on my own.
I know this chart relates to diatonic chord progressions. It is suppose to show the complete inter-relationship of musical notes and intervals. If I am reading this correctly, if you move clockwise, the circle rotates in 5ths (V) ie: the 5th (V) of the C is G. If you move counterclockwise, we are moving in the direction of 4ths (IVth) ie: the I4th (Vth) of a C is an F. The same is true for the minor scale shown below. The inner minor circle seems to link the Major key to the 6th (vi) ie in the key of C the 6th (vi) is a Am and so on. Now this is where things get a little funky. If I move from the C, down diagonally to the left, I get a ii or Dm. Likewise, if I move down from the C to the right, I get the Em or iii. If any of this is true, (and it seems to be) there is a lot more here than just a “circle of fifths”. Also, I don’t know what role the diminished seventh plays in all of this.
I love your course, and have reviewed some of the lessons several times. However, because I had a musical background, I seem to want to take your course material and run with it. I stumbled on the Circle of Fifths sometime ago after finishing your module on fifths., thirds and sevenths. I am just now trying to wrap my head around this. Any help or suggestions you have would be greatly appreciated. Maybe this would make a great course topic?
I suppose you could try to glean data about diatonic chord progression here, but this is more about keys than chords. That’s why there’s no diminished seventh chord anywhere - the major/minor designations aren’t talking about chords (primarily at least).
The only big thing that’s missing from our discussion so far is the helpful role this chart can play in remembering key signatures -which are missing from this version of the chart. Here’s one with more data (and more colors )
relative minor/major keys share a key signature (i.e. C major and A minor, same notes, same key signature)
You can also see how different interval movements will affect key signature. For example, if you skip one key and go from C to D, which is a whole step, you add two sharps (or if you jump back to Bb, you get two flats). So you can file that away and know that any time a song modulates up a whole step, for example, there will be two notes that change from the previous key.
@Gio, anything to add? Curious if you ever use the circle to talk about chord progressions like Brian was talking about, I’d actually never heard of it being used like that.
I haven’t used the circle to talk about chord progressions the way you were with the ii and iii chord, @bsickels. The chord progression magic happens when you watch root movement around the circle of fourths (or, as the classical cats call it, falling fifths) - but it isn’t key signature or chord quality relevant - it’s only root relationships.
(as in iii-vi-ii-V-I … in whatever key, it’s moving in fourths the entire time, the chord quality changing to fit the key you’re in)
The closeness of the ii and iii seems like happy coincidence. If it’s helpful, awesome. But I don’t think it fits in to much application or practice that I’ve run across.