Jim Shumate (1921 to 2013). Fiddler on early Monroe and Flatt and Scruggs recordings who talked Monroe into hiring Earl Scruggs.
Why this player is listed
Jim Shumate appears in the Play Bluegrass guide to notable fiddle players, which collects contest champions, bluegrass fiddlers, Canadian fiddlers, judges, and departed legends tied to the tradition.
More fiddle context
For the larger list, start with the big list of fiddle players. For the style itself, read the guide to bluegrass fiddle.