How to solo over a 12-bar blues
The 12-bar blues form, the scales that work over all of it, and the trick that makes a blues solo follow the changes: aim for each chord’s 3rd.
Updated
The 12-bar blues is the best place to learn to improvise: three chords, a form that repeats, and a sound where "rough around the edges" is the point. Here's the form, the scales that cover all of it, and the trick that makes a blues solo sound like it follows the band.
The form
A 12-bar blues in A uses three dominant 7th chords — the I, IV and V of the key: A7, D7 and E7. One chord per bar:
- Bars 1–4: A7 · A7 · A7 · A7
- Bars 5–8: D7 · D7 · A7 · A7
- Bars 9–12: E7 · D7 · A7 · E7
The last bar's E7 is the turnaround: it pulls you back to A7 and the top of the form. A common variation, the quick change, plays D7 in bar 2. Count the bars out loud the first few times — knowing where you are in the twelve is half of soloing over them.
One scale for all twelve bars
The A minor pentatonic — A, C, D, E, G — works over the whole form. Its C clashes with the C# of A7, and that clash is the blues sound: a minor-sounding melody over major-sounding chords. Add the ♭5 (E♭) and you have the A blues scale, the scale of a thousand licks.
A blues scale
6 notes
- A1
- Cb3
- D4
- D#b5
- E5
- Gb7
For a sweeter, more country or soul sound, switch to the A major pentatonic — A, B, C#, E, F#. The best players move between the two in the same solo.
Follow the changes: aim for the 3rds
Playing one scale over everything works, but it doesn't follow the chords. The trick is to land on each chord's 3rd when it arrives:
- over A7, aim for C# — a half step above the scale's C, so bend or slide C up to it;
- over D7, aim for F# — or play the scale's C, which is D7's own ♭7 and sounds right at home there;
- over E7, aim for G# — a half step below A, a strong pull back home for the turnaround.
That one move — the C you've been playing becoming C# on the A7, or C as the 7th of D7 — is what makes a blues solo sound like it knows the form.
Phrasing: call and response
The blues is built on conversation. Play a short phrase (the call), leave space, answer it (the response). The classic shape follows the form's three lines: a phrase over bars 1–4, the same phrase again over 5–8 (it sounds different over D7 — that's the point), and a different answer over 9–12.
- Bend into notes rather than just fretting them — the D bent up to E on the G string is the sound of blues guitar.
- Use repetition. A two-note lick repeated over the I chord builds tension that the IV chord releases.
- Swing it. Most blues is played with a shuffle feel: long-short, long-short.
Play it over real blues
Every blues record bends the form a little — an extra bar, a minor iv, a jazzy turnaround. Upload one to easyimprov and it finds the key and the chords bar by bar, and shows which notes to aim for on each change as the record plays.