Brucie, I have read many comparisons of bluegrass to rock music when it comes to energy level.

One word that I don't believe that has come up when it comes to playing bluegrass in a group is discipline. The discipline that is needed by each musician to make a bluegrass group sound successful (and in the best sense of the word, differentiated) is what I consider makes so many exceptional bluegrass players the vituosos that they are.