There were rehearsed jokes , gags and practiced eye-rolling among his Clinch Mountain Boys ; businesslike introductions by Mr. Stanley 's 13-year-old mandolin-playing grandson , Nathan Stanley ; numbers spotlighting every member of the band ; a commercial break to advertise Mr. Stanley 's annual bluegrass festival near Coeburn , in southwestern Virginia , -LRB- '' just about 600 miles south of here , '' said the band 's good-natured guitarist , James Shelton -RRB- ; and places in the set for Mr. Stanley to sing his grieving a cappella mountain music and play claw-hammer banjo .