Comprising more than 400 competitive categories of music, dance, and elocution (poetry and public speaking) events, the Kenya Music Festival (KMF) provides an opportunity for over 130,000 Kenyan students to demonstrate their artistic abilities at the national level, with countless more participating at local and regional levels. One of the central components of KMF is the adjudication of these competitive classes, with students and ensembles vying with each other for trophies, prizes, and recognition. Winning performers may be invited to perform for the President of Kenya and other high dignitaries, and winning teachers and conductors receive peer recognition and often professional advancement. Both the scope and the consequential nature of KMF make it a notable example of national-scale assessment of music learning and performance. We conducted a case study of the adjudication process at KMF, drawing on observations of adjudication at the national festival, engagement as a participant-observer in a national workshop for teachers and adjudicators, and interviews with nine experienced adjudicators. Understanding the adjudication at KMF sheds light on how organizers, adjudicators, and participants view the assessment process, what criteria they find to be most important in assessing music learning, and how national music assessors are identified, prepared, and evaluated. Preliminary data analysis indicates that KMF adjudication is heavily influenced by the community of practice existing around the festival itself, as well as a more select community of practice formed by adjudicators. Participants noted that historically, adjudicators have not been required to receive formal training or certification. As a result, adjudicators rely heavily on their personal backgrounds as performers and conductors at the festival to establish their understanding of norms and standards. Adjudicators also draw on their pre-existing experience with specific genres and cultural backgrounds, supplementing this with independent study using whatever resources are available to them. In recent years, the festival has implemented a standardized assessment tool: a scoring sheet including a list of evaluative categories, each with a specific point value. Participants generally indicated a favorable view of this tool, and researcher observations and participant statements suggested that the traditions of the adjudicators’ community of practice often influenced its implementation. Participants expressed strong optimism for both the current state of assessment at the festival and continued future growth. To conclude, we will present connections with the existing literature on music assessment and implications for the international music education community.