Yes, Stewie. One of the city boys (played by Roy Scheider, I believe) plays a run on his guitar, which is repeated by a local lad on his banjo. The banjo player appears to be inbred/retarded, sort of an "idiot-savant" (underscoring the later concern in the story that any local jury will be populated by relatives of the man the city voyagers felt forced to kill). The guitarist steadily increases the tempo and complexity of what he's playing, while the banjoist flawlessly keeps up with him, then takes off with it and pumps the notes out so fast that the guitarist stops, saying "I can't keep up". In the movie, the last part of the tune is thus banjo only.