Watch the Alabama Jubilee online guitar lesson by Brooks Robertson from Essentials: Boom-Chick Fingerstyle Etudes
As you review the performance video, notice the use of left (fretting) hand muting/muffling being used in addition to the palm muting with the right (picking) hand. This is a very important technique used for accenting, punctuation, dynamics, and the overall feel. Essentially, the pressure is released from the fretting hand, just enough for the strings to stop sustaining, without the fingers leaving the strings. Another concept to watch and listen closely to is the open string chromatic run, which uses a banjo roll technique.