This chapter introduces Eloise Knapp Hay’s (1984) concept of dual biography and explains why Dylan and Lennon are such appropriate subjects. It examines their known meetings, intertextual references, reciprocal influences and other forms of interaction. As the dual biography unfolds it elicits findings that a study of each performer alone could not disclose. The cultural mythology around their fleeting encounters, such as when Dylan apparently introduced the Beatles to marijuana or when Dylan and Lennon filmed a cinéma vérité scene together, demonstrates the symbiotic nature of their ongoing relationship.