Playing the 12 bar blues on bass in 3 simple steps.
Step 1- Playing The Root Notes
The first step is to follow the chord changes of the 12 bar blues. We do this by playing the root note of each chord. The 12 bar blues uses the 1, 4, and 5 chords of the key your in. In the case below we’re in the key of A, so our chords are A7, D7, and E7. So the notes you’d play are A, D, and E the root notes of those chords.
STEP 2 – Playing Chord Tones
In the second step we add more complexity by using arpeggios or chord tones. The chords in the 12 bar blues are always Dominant 7th chords (they are commonly just called 7th chords). When you play the arpeggios you’re just outlining the chords in the song note by note.
STEP 3 – Adding OUTSIDE or Jazzy Tones
In the third step we add even more complexity by using tones outside the chord which is the icing on the cake when playing blues. These colour tones add spice and interest to your bass line. The intervals below the 3rd (b3rd) and the b7th (6th) are used almost extensively in blues.