Crossroads (1986) on Netflix

Eugene Martone, the "Lightening Boy", is a lover of blues. He studies guitar in Julliard, but he indeed is looking for the thirtieth unknown song of Roberto Johnson. One day, he meets Willie Brown, the "Blind Dog" in an old folk's home and is convinced that he possess the lost song. Eugene helps Willie to escape the asylum and goes with him to Mississippi. They can just afford a bus ticket from New York to half way to Mississippi, so the rest of their journey is hitchhiking. In the way, they meet Frances, a girl who left home and wishes to be a dancer in Los Angeles. They three together pass through many strange adventures and situations, and the climax is the guitar duel between Eugene and Jack Butler.