What is the main conflict in Reservation Blues by Sherman Alexie?

Legendary blues musician Robert Johnson, rumored to have sold his soul for his success, trying to rid himself of his magic guitar leaves it in a Spokane, Washington Indian reservation where Thomas Builds-the-Fire picks it up. Thomas with Victor Joseph and Junior Polatkin form a garage band called Coyote Springs and success follows them quickly as Cavalry Records executives take an interest in them. Reservation Blues pairs comedic style with magic realism while tackling the trials of the modern Native American on reservations.