Here are a couple great ways to modify your main chords in the key of D. We can play a Bm7 chord instead of a regular Bm, and we can play different varieties (or “substitutions”) of a D chord, such as a Dsus2 or Dsus4, etc.

In this video we follow a familiar theme: we start with a major chord, walk down to a minor chord, and then use a “turnaround” to resolve back to our starting chord.