In the hundred years that saw the widest effects of industrialisation and immigration to Wales, the popular music of the country embraced an increasingly passionate and secular adherence to traditions derived from choralism and eisteddfod culture on the one hand, and the development of commercial popular music on the other. ‘Popular music’ was defined not by repertoire but by the circumstances of its performance. Major features of this story include the first conspicuous appearances of Welsh choralism outside Wales, the world’s first virtuoso private brass band, Welsh manifestations of music hall and romantic theatre music, the rise of tourist entertainment and the projection of Welshness in the early years of broadcasting. One of the more interesting features of the period is the way Wales digested broader trends in popular music, modified them and projected them in distinctive ways. The chapter paints a picture of Welsh musical life that is seldom seen, in which strong musical traditions steeped in the culture of the Welsh language coalesce with popular modernism and new types of musical commerce and consumerism.