I consider rhythmn guitar to be a specialty of mine, and along with the bass, the glue that holds everything together.

Over the years, I have developed a type of cross-picking style of rhythm guitar that helps establish a precise timing of a song. Like the bass, the rhythm guitar acts a timekeeping instrument. Unless, by design, songs should not slow down or speed up, but I believe should remain consistant.

I own both small bodied guitars and full size dreadnaughts and find the "D" sizes to be the best in driving a full bodied rhythm.

One of the great rhythm players in all of folk music I believe was Bob Shane of the Kingston Trio. He could make a D28 chug like a steam engine when necessary, and his timing was impeccable.

Dynamics is also a big part of rhythm guitar playing, when to back off and when to drive it home. In bluegrass, I don't care how flashy your lead players are, the rhythm guitar is the foundation. Check out Dan Tyminski in Allison Krause's Union Station