Guide Tones

Here is the thing nobody tells you early enough: you do not need to know a new scale for each chord. You need to hit two notes.

The third and the seventh of a chord are its guide tones. The third says whether the chord is major or minor. The seventh says whether it is a major seventh or a dominant. Between them they identify the chord completely — the root and fifth add nothing you did not already know, and the bass player is covering the root anyway.

So when you improvise over changes, aim at guide tones on the downbeats. A line that lands on the third or seventh of each chord as it arrives sounds like jazz, even if everything between those landings is simple.

Work out a few before you play. Over Am7 the third is C and the seventh is G. Over Dm7 they are F and C. Over G7 they are B and F. Over Cmaj7 they are E and B. Notice how little movement there is between those pairs — that is the other reason guide tones matter: they connect to each other by a half step or a whole step, so a guide-tone line practically writes itself.

A guide-tone line: Am7, Dm7, G7, Cmaj7

One note per bar, all on the D string. G is the seventh of Am7, F the seventh of Dm7, F again the seventh of G7, E the third of Cmaj7. Three of the four barely move.

e
B
G
D
A
E

-----|-----|-----|-----|
-----|-----|-----|-----|
-----|-----|-----|-----|
--5--|--3--|--3--|--2--|
-----|-----|-----|-----|
-----|-----|-----|-----|

This track is a ballad at 70 BPM in A minor, and it is slow on purpose. Its changes move through Am7, Dm7, G7, Cmaj7, Fmaj7 and Em7 — all chords whose guide tones you just worked out.

Play one note per chord. Just one. Land on a third or a seventh as the chord arrives and hold it until the next change, then move to the nearest guide tone of the new chord.

That is a real jazz solo, played at one note per bar. Speed is the last thing to add, not the first.

A 70 BPM ballad in A minor. One note per chord, always a third or a seventh.