Another important chord type is the Dominant 7th chord (commonly called a 7th chord). Here are the most common shapes for these chords.
C7
G7
D7
A7
E7
B7
It is possible to find alternative fingerings for the chords shown here. Once you know which notes make up a particular chord, it is possible to arrange the notes in any order as long as the fingering is practical. The following example should help you become familiar with these basic 7th chord shapes. The B7 chord is used in the 12 Bar Blues in E (exercise 58).
12 Bar Blues can be played in any key (i.e., starting with any note or chord). In Blues, the name of the first chord is usually the name of the key also. The next exercise is a Blues in the key of D, which uses a less regular rhythm than the previous one. This makes counting essential so you don’t lose your place in the music.
The next example is a 12 Bar Blues in the key of E. It contains the chord B7 which was shown earlier in this lesson. Practice changing between B7 and all the other chords you know until it becomes easy.