If my flapper ears doesn't cheat me, I hear the following chords with the banjo.
In the first and second part lots of D and very short A, and reminds me immediately to Sally Goodin or Indian on a Stomp
In the third part I hear Bminor for sure and A.
If this is called a modulation , I'm not sure.
That's because the A-chord doesn't change
I thought that a modulation changed the key of a whole song ?