Instead of piggybacking this material onto other threads such as the Q & A sticky, i thought i should probably start my own, and so... here we are. Welcome to my Functional Harmony thread! Many of the concepts we will be discussing here are things that i have attempted to incorporate in the Practical Jazz and Practical Music Workshops that i've hosted personally, so please excuse any repeated information if it's something you've already seen and have internalized. This first post will definitely duplicate what i've posted elsewhere but since it's really the basis for everything else we'll be talking about here, its reiteration is not a bad thing. i'm just going to leave this here for future reference: It is the 'key' to unlocking so much of functional harmony. Study it, figure out the various patterns it contains... and you will travel far along the path of musical righteousness. First step: Look at the circle of 5ths diagram above. The Outer Circle spells out the 12 diatonic Major Keys. Starting from the key of C at the top, as we rotate clockwise, we move upwards by the interval of a perfect 5th each time, and each new key adds one more accidental, which will be a sharp (#)... C (no sharps), then G (one sharp, which occurs on the 7th scale degree), so G A B C D E F# and then back to G, the 8th scale degree, or octave. The D Major scale would be the next in line, and we retain the F# from the previous key, and add one more sharp on the 7th scale degree of our new key: D E F#G A B C# D. In A major we would carry over both sharps from the previous key, and add one more on the 7th degree once again, so we now have: A B C# D E F# G# A The Major scale pattern is always the same, with half steps occurring between steps 3 and 4 and between 7 and 8. If we look at the diagram again and move counterclockwise from C this time, we are still ascending (this is the tricky part visually and conceptually), but by the interval of a perfect 4th now, and each click in that counterclockwise direction adds one flat (b). C (no flats, the only 'natural' major key), then F Major (one flat): F G A Bb C D E F. For the next key, we keep the Bb (obviously, since it's now the root or 'tonic' of our new key, LOL), and add one more flat on the new key's 4th step to arrive at Bb Major: Bb C D Eb F G A Bb The next counterclockwise key is Eb Major, and guess what we're going to do? That's right, the previous key's 4th step has again become our new tonic , and now we'll carry over our previous flats, and add another one to the new key's 4th step: Eb F G Ab Bb C D Eb Next key: Ab Major: Ab Bb C Db Eb F G Ab Are you starting to see the patterns? Each new clockwise key moves to the 5th, keeps any previous sharps, and adds a sharp to the new key's 7th scale degree. Each new counterclockwise key moves to the 4th, keeps any previous flats, and adds a flat to the new 4th scale degree. At the bottom of the circle is F#, which is also enharmonic Gb (in equal temperament, of course, LOL again). "Ahh, but if I'm counting backwards, aren't I going down 5 steps, not 4?", i hear you saying. Yes, in fact you are... welcome to the world of inversions. A lot of basic music theory is actually just simple math. Any given interval plus its inversion gives a sum of 9. So up 5 steps will give you the same pitch name as down 4. Conversely, up 4 steps will give you the same pitch name as down 5. And up 6 will give you the same pitch name as down 3. Try it: C D E F G A B C... move up 6 steps starting from C, and you will arrive at A. Count back 3 steps from C, and you get back to... wait for it... A again. Count up 3 scale degrees from the C and you arrive at E. Count down 6 scale degrees from C and you are back at E once more. Add 6 + 3, and the sum is... 9. 9 is our magic number when it comes to inversions. Major intervals invert to minor ones, and minor intervals invert to major ones. A to C is an interval of a minor 3rd, while C to A is an interval of a major 6th. The exception to this: 4ths and 5ths are 'perfect' intervals, so they stay major either way. We'll look at inversions a bit more closely when we get into chord construction later on. Stay tuned... next we'll enter the 'Inner Circle'... but we've already received the 'key' to the door.