The following blues progression uses the C7 chord shape played at the first fret (C7), the 6th fret (F7) and the 8th fret (G7).
C7
F7
G7
* This pattern can be expanded to use 6 strings:
Once again, the bass note is alternating between the 5th and 6th strings and is played in a staccato fashion. Bass note runs are used between the chord changes (refer to the tablature for the correct playing position of these runs).