We’ve been talking a lot on the blog lately about improvisation methods and systems. The guitar is a double-edged sword in this regard as a solo can be approached in many ways depending on the player and the desired result. Whatever your style or genre is, and if you’re going the scales over chords route, you’ll want to consider these two golden rules to make the most of your moment of glory.

Here are the two golden rules:
Rule 1. Any scale that contains ALL the chord tones from the chord you want to solo over is fair game.
Rule 2. Knowing the function of the chord in the progression will allow you to find the scale that best fits the chord.Let’s take a more in-depth look at these two approaches.

Rule 1 states that as along as the scale contains all the chord tones of the chord we want to improvise over, we can use it. Let’s try it out over a dominant 7 chord. A dominant 7 chord contains the intervals 1, 3, 5, and b7 so according to rule 1, any scale that contains those intervals is fair game – and there are plenty of them!

If you have a looper pedal handy, load it up with a C7 chord. If you don’t have a looper, you should really treat yourself to one – I recommend either the TC Electronic Ditto or the classic Boss RC-1.

Your first port of call over a dominant 7 chord will probably be the Mixolydian scale which contains the intervals from our dominant 7 chord: 1, 2, 3, 4, 5, 6, b7

Here’s a quick pattern you can use to get this going.
combining scales with chords
I’m a huge fan of these one-octave shapes, especially with the added 7 below the root – it comes in very handy for phrasing purposes.

As you’d expect, the Mixolydian b6 scale also contains all the chord intervals, plus a b6 (1, 2, 3, 4, 5, b6, b7). Here’s another quick pattern for you, or you could just lower the 6 from the above pattern.
how to combine scales with chords
If you’ve never used this scale before, the b6 will throw you off at first. Take some time to work it into your lines and you should come up with some interesting stuff before long.

Check out the Lydian b7 scale, which contains the intervals 1, 2, 3, #4, 5, 6, b7

Again, all the intervals from the chord are in there so it’s fair game. Here’s a quick pattern:
scales and chords guitar
Here’s another scale you could use over a dominant chord, the Phrygian Dominant, which contains the intervals 1, b2, 3, 4, 5, b6, b7:
soloing over chord changes
Making it Work
To make this work, you need to get comfortable with these scales. Remember, you don’t have to use all of them, and you may not even like how some of the them sound. If you do like the sound of a particular scale, then work on getting the most out of it so that next time you go to solo over a dominant 7 chord, you have it in your arsenal.

Rule 2 states that you can choose a scale based on the function of the chord. This is easier than it sounds and simply requires you to analyze the chord progression of the tune you want to improvise on.

Let’s take the following changes in two sections:

Dm | Am | C | Gm | Am

Bb | F | Gm | Dm | Bb | F | C | Gm

Load the first section into your looper but give yourself plenty of time on each chord.

When analyzing a chord progression, first ask yourself what key it’s in. The one above is in D Minor (relative minor of F Major).

Then write out the chords in the key:

 F | Gm | Am | Bb | C | Dm | E°

Next, match up the modes to each chord:

F Ionian | G Dorian | A Phrygian | Bb Lydian | C Mixolydian | D Aeolian | E Locrian

Basically, if you want to improvise over any section of this progression, you simply use the corresponding mode. For example, over the Dm you play D Aeolian, over the Am you play A Phrygian etc. It may seem like a tall order at first (this is why I said to give yourself plenty of time on each chord), but when you start to blend the modes together, you’ll get some amazing results.

If you’ve dabbled with modes, you’ll realize that all the above modes contain the exact same notes, just starting on a different root (modes in a nutshell), so why can’t you just blow over the entire progression with one scale? You could… but it’ll sound a bit hit and miss, unless you have a very good ear, because you’re not actually considering which chord you’re improvising over. If you at least respect each chord’s mode, you’ll get a better-sounding result because of the arrangement of the notes i.e. A Phrygian starts on A and all your licks and runs will need to relate to A. If you’ve decided to blow over it with one scale, perhaps D Aeolian, it won’t sound bad, but you’ll be relating everything to D over every chord.

As long as you give these two approaches a little time, you’ll start to see some great results.