Tritones

Music Lesson: 12-Bar Blues in F

So whether you sung the melody of "All of Me" or just used these accompaniments we looked at to accompany somebody else, it's an invaluable skill to have, especially if you ever find yourself in a duo situation as well.

Introducing the 12-Bar Blues

We're going to apply all these techniques now to blues, specifically the 12-bar blues, starting with the blues in F.

Chords in F

You'll remember from part one that, for instance, in shell blues, all the chords have dominant sevenths. So in F, that's:

• F7
• Bb7
• C7 (the IV and V chords)

Tritones

Now, you'll also remember we played those as tritones. A tritone consists of the third and seventh of the chord.

"This is this magic interval which can be played flipped over or inverted, and it's still a tritone: seventh and third or third and seventh."

This has some important ramifications for a blues in F.

• If you play F like that, when you want to go to the IV chord in bar 5:
  • Instead of doing the same thing on Bb, flip it over, and then you'll be just a semitone lower.

So that's how you go from I to IV: you just move down a semitone with your tritone.

• And guess what you need to do to go to V?
  • Go up a semitone. How cool is that?

Flexibility in Improvisation

We're going to be doing this in the left hand if you're improvising but also in the right hand if you're playing a bassline. So it's good to be flexible either way.

Jazzy Turnarounds

One last thing to mention before we embark on our blues in F is that the last two bars often use a jazzy turnaround, a 1, 6, 2, 5 turnaround like we saw earlier.

• In this case, rather than being diatonic, it's going to be dominant sevenths all over the place:
  • F, D7, G7, C7.

Now notice how neat that works out when you play tritones. Your D7 tritone, F# and C, goes down in semitones, followed by G7, C7, and back to F.

Practice Tips

• Practice that over and over, maybe with some bass notes.
• Alternatively, you could do it the other way around, using opposite tritones.

This turnaround figure just happens once at the end of every 12-bar section in the last two bars.

"Don't do it on the final one because you need to do an ending."

And you'll notice I provided you a different ending in blues comping with two-feel bass.