 Country tuning raises the initial F by a semitone to an F. This primarily aids in harmony in the key of G, facilitating easy play of the G-C-D (I-IV-V) chord progression, while maintaining a partial G7 (minus the root) higher on the harmonica.It can occasionally be helpful in some melodies, most notably "The Star-Spangled Banner," which has a low F# and a high F. For example