When John wrote “Indiana Firefly,” which he recorded on his album Up in the Woods, he was trying to come up with something Bill Monroe might write. It’s in the key of A with an interesting chord progression in the first part (A, D, C, G) and a melody that has more of a minor or Dorian sound. John starts by walking you through the melody to the A part, showing you how the melody is based on the underlying chord shapes. Then he shows you the B part, which moves more to a major tonality, starting with E and A major chords.