The two notes that define a chord
Take Dm7: D F A C. The root (D) and fifth (A) are supporting; the 3rd (F) and the 7th (C) tell you what chord it is. In a ii–V–I (Dm7 – G7 – Cmaj7) these guide tones move by the smallest possible steps: the 7th of one chord falls to the 3rd of the next.
- Dm7: F and C
- G7: B and F
- Cmaj7: E and B
This is the heart of smooth voice leading (see the voice leading drill) and the reason ii–V–I sounds so natural. Colour tones on top (9ths, 13ths) do not change the guide tones: see the chord colours guide and the Voice Leading in Practice program.
Frequently asked questions
What are guide tones?
The 3rd and the 7th of a chord. The 3rd tells you whether it is major or minor, and the 7th tells you what kind of 7th chord it is. Together they define the chord, which is why they are the notes to follow when you connect chords.
Why do the guide tones move so little?
In a ii–V–I the 7th of each chord falls by a step to the 3rd of the next, and the other guide tone stays put. For example in C: Dm7 (F and C), G7 (F and B), Cmaj7 (E and B). Two smooth lines, hardly any movement.
How do I use guide tones when I play?
On piano or guitar, play just the 3rd and 7th (with the root in the bass) and move them as the chords change. Then add colour on top: 9ths, 13ths, whatever you like. The skeleton stays smooth.
Do guide tones work for colour chords?
Yes. A 9th or 13th is built on top of the 3rd and 7th, so the guide tones stay the same however colourful you go.