Not specifically about modes, but BBC’s History of Music in 50 Pieces podcast is excellent to learn about the development of scales, thirds, and harmonies in Western music over the centuries, and a lot more!
The question of the perfect fifth has been simmering in my mind for some time now. It started when we started investigating chord substitutions on Song Talk Radio in 2016. For that show, I looked at the Circle of Fifths as a great tool for making chord choices when writing a song. The Circle of Fifths describes tonal and chord centre relationships within the 12-note equal temperment scale we use in Western music. The most common cadence in songwriting or composing is a V – I (e.g. G-major to C-major in the key of C-major).
People, especially musicians, say that music is a universal language. This part of the question came to me when my older brother decided to learn how to play guitar, never having studied music in the past. He asked me if the scales we use and notes we use are based in anything scientifically true. So, think back to your math and science classes, we’re about to nerd out…
It’s all about the ratios
Let’s start with the most basic of tonal relationships: the octave. The octave to any note, as we know, is the same note name, either higher or lower. We can represent a note visually by a single frequency (nerd alert: this is a basic representation of a fundamental frequency, ignoring the harmonics that make up most sounds):
And its octave above is a note that is twice the frequency (purple line):
Notice how the black line (base octave) completes one cycle for every two cycles of the purple line (octave above) – a ratio of 1:2. The cycles intersect frequently and in a clear, simple pattern. This is why two notes, an octave apart, sound the most harmonious and pleasing. Regardless of the specific tuning standard (the vast majority of us use the A4=440 Hz standard), or what your base note is, this relative relationship holds true. Read more
I know many of you don’t care for music theory. It’s clinical, it’s boring, and it sucks the soul out of songwriting. Well, news flash: you’re using music theory whether or not you intend to. For myself, I know my theory pretty well, as I learned it at young age. I couldn’t tell you if I’m playing in a Mixolydian or Phrygian mode, though, except that it’s fun to throw “Phrygian” into normal conversation.
Case in point: the Circle of Fifths (the Circle). Download a hi-res copy here. I’ve been asked before if a certain chord progression is an example of the Circle of Fifths. The question is missing the point. The Circle of Fifths isn’t a technique like modulation or chord substitution. It’s a way of understanding the essential elements of western music: the notes, the intervals, the chords, and the relationships between them.
It’s the relationships between chords that make a chord progression. Referring to the Circle of Fifths can help you discover interesting chord progressions, particularly when you’re stuck for what the next chord wants to be.
Just like clockwork
The Circle looks much like a clock. Just like there are 12 hours on a clock, there are 12 notes on the Circle. (If you haven’t downloaded a copy yet, you’ll want to so you can refer to it as you read the rest of this article.)