This paper presents the results of a doctoral research that aimed to analyze the processes of musical learning and the practices that emerged within, and were triggered by, the Student Music Festival of Guarulhos - Brazil, conceived as a competitive event. The central objective of the Festival was to mobilize the schools of the municipality of Guarulhos and to provide visibility to their pedagogical initiatives in the field of music. Organized by the Municipal Department of Culture, the Festival involved teachers, school administrators, municipal managers, and, above all, 23 musical groups formed by young students. The Festival was open to all configurations of instrumental and/or vocal ensembles and embraced all musical styles and genres, which resulted in a remarkable diversity of playing and singing styles. Structured in two semifinals and a final stage, the event awarded the ten finalist compositions with professional studio recording. For the purposes of this research, the Student Music Festival of Guarulhos was taken as the central case, considering that its dynamics and organizational structure enhance the possibilities for musical learning among participants. The study was grounded on the premise that musical knowledge can be constructed in diverse contexts and through multiple modalities of engagement. The research followed a qualitative approach, employing the case study as its methodological framework. Fieldwork extended over a period of eight months, during which data were produced through: observations documented through photography and audiovisual recording of the qualifying rounds and final stage of the Festival; semi-structured interviews conducted with members of the musical groups, pedagogical teams from the participating schools, and the Festival’s organizing committee; and documents related to the event. The data collected allow for a comprehensive understanding of the dynamics, organizational structure, and pedagogical-musical potential inherent in this type of cultural initiative. Throughout the Festival, several instances of significant musical learning were observed, such as the preparation of students for their performances and the opportunities provided by the organizers for interaction with professional musicians, who offered guidance and technical insights. The Festival proved to be a catalyst for the musical practice of numerous young participants and reshaped the school environment by stimulating the engagement of students and teachers in composition, band formation, and musical performance. The findings indicate that the Festival extended beyond the formally established spaces and timelines of its organization, permeating the lives and musical trajectories of its participants.