Abstract Abundant research supports the idea that musical training improves to a large extent the development of hearing ability in children. This auditory development is linked to an enhancement in the language learning process, mainly in the oral and aural skills (Magne et al., 2006; Hyde et al., 2009). The implementation of a new methodology, Music as a Medium of Instruction (MMI) –based on EMI theory features-, takes advantage of the benefits that music provides in the teaching of English as a second language, leading to more efficient results. The differences in terms of progression between students with previous musical training and non-musician students is also detailed throughout the practical case study of this research, which experimental design provides an in-depth analysis. The results come from an analysis of the confidence interval, built with quartiles based on t-distributions governing each of these groups, and a probability calculation of the MMI method success presenting different dimensions of the study. The results obtained reveal that MMI methodology stands out for its improvement in the oral and aural learning process. Students enjoy with music in lessons and therefore more receptive learning come to fruition. The ability to motivate and the entertaining spirit that music awakens in students, make the teaching-learning process a rewarding experience where they learn and teachers instruct significantly through action and fun. The development and implementation of this methodology within the school curriculum would lead to performance enhancement in the teaching of a second language.  KEYWORDS: music, second language acquisition, brain, education, methodology, musical training.