The chapter examines the relationships between music, sport and Welsh identity. Focusing on the national rugby union and football teams, it explores the ways in which performances of ‘Mae Hen Wlad Fy Nhadau’ by players and supporters have contributed to a cohesive sense of national identity. Examples range from its first recorded use prior to the rugby team’s famous victory over the New Zealand All Blacks in 1905 to its part in the Football Association of Wales’s efforts to galvanise supporters during the team’s successful Euro 2016 campaign. It also considers the adoption of popular hymns such as ‘Guide Me, O Thou Great Jehovah’ and ‘Calon Lân’ by supporters, investigating the extent to which affiliation to the national team takes on a spiritual quality. Drawing on the contributions of popular Welsh artists such as Max Boyce, the chapter also assesses the self-referential nature of connections between musicality and sporting pride in corporate expressions of national identity. It considers the ways in which language, religious practice and social structures encouraged and maintained a culture of massed patriotic singing, and how this has been reimagined and perpetuated in the twenty-first century through a combination of institutional support, technological developments and the influence of social media.