Theory Bass-ics: Functional Circle-of-Fourths for Blues
I’m still lurching towards finishing the e-book, but in the meantime I want to expand on a concept that I wrote about in the last Theory Bass-ics: understanding how chords relate to the circle-of-fourths.
Recently, I started using a chart that I call the “functional circle-of-fourths” in my teaching. In it, the tonic (or Roman Numeral I) is at the top of the circle and the rest of the chords are graphed out by harmonic function. This version is for “C Jam Blues” (see below for chart), which is in ‘C’ and has a very simple harmonic progression:
The reason that this model is helpful is that it makes it easier to understand (and memorize) chord progressions in tunes. Most of us know that I-IV-V is the typical “3-chord progression” in blues and rock, but we don’t think about how all three are adjacent to each other at the top of the circle-of-fourths. And as I mentioned in the previous Theory Bass-ics post, it’s easier to understand ii-V-I progressions if you can visualize them on the circle-of-fourths.
“C Jam Blues” is about as basic as it gets in terms of chord progressions (and with the added bonus of being in the key of ‘C’). In future posts, I’ll analyze more complicated tunes using this model (I’m already making my students do similar analyses for each of our tunes – which is equal parts frustrating and productive for them). Stay tuned!