The name John Mitchell is indeed common that even in the first times of the recording industry it had been possible to botch the identities of instrumentalists dubbed thusly. Hillbilly music and traditional jazz had been both popular designs in the ’20s and ’30s, each using its personal John Mitchell, perhaps a few. The John Mitchell who performed tenor banjo and acoustic guitar in hillbilly documenting bands shouldn’t be confused using the jazz banjoist and guitarist who spent the majority of his profession in Europe.