Another common minor 7th shape occurs at the crossover point between the G form and the E form. The minor ninth chord is an extension of the minor 7th. With the minor seventh it is common to slide the part of the chord played with the 3rd finger up two frets, as shown in example 307.
X Am7 X
X Am9 X
This 12 Bar Blues shows a typical way of using these chord shapes. Notice the use of sliding chords and percussive strums.