There are several approaches to thinking about (and memorizing) 7th chords.  The first one we examine is through stacked thirds.  First, we look at this theoretically, and in a future video, we will highlight how to use this theoretical knowledge on your instrument, to identify those sevenths chords without going through scale degrees or diatonic chords, for example.  Understanding this concept may be key in developing a chunking strategy, especially as you add more chords to your arsenal.  This is a theory video.