This track is intended as an exercise for students who have recently been introduced to 7 Chords. Once they are familiar with the shapes this track is a good way of putting them into practice and using them between chords they’re already familiar with.
You can review the Basic Open Chords and Open 7 Chords lessons to remind yourself of the chord shapes. The cool thing about the first 2 bars is that you only change one finger between every chord.
This can also be used as a backing track for solo guitarists. The key CMaj / Am.