Starting with a brief review of the question, this article examines evidence stemming from classical, popular and ethnic music, as well as from the field of language-based taxonomies and other research areas, that seem to prove a strong correlation between aural environment and musical production. To explain these interesting phenomena, we propose the sonic affinity theory, which holds that the human musical brain is shaped by the action of surrounding sounds, which generate aural profiles and aesthetic patterns in complex reflective processes. The ability to unconsciously internalize auditory signals is the result of an adaptive evolutionary mechanism and develops into a sonic affinity.