Dustin Wilkes, a University of North Georgia student who has performed with music legends such as Willie Nelson, will be a guest performer as the university explores American music Saturday at the UNG campus in Gainesville. Wilkes, who grew up in nearby Jackson County, Ga., worked in the music industry for several years and in 2007 was a finalist on “Nashville Star,” a reality competition show patterned after “American Idol” featured country and bluegrass musicians. Prior to that, Wilkes served in the U.S. Marine Corps for five years and wrote the song “One Toy at a Time,” while volunteering for Toys for Tots.