This thesis studies the structural transformation of public musical life in Stockholm during the period 1840–1890, with focus primarily on the classical musical sphere. The study is based on qualitative and quantitative analysis of a number of different sources such as newspapers, music magazines, offprints, and other archival material. Using Jürgen Habermas’s theory of structural transformation of the public sphere as a starting point, the thesis aims to elucidate the processes within the structural transformation of Stockholm’s public musical life. In particular, this study examines processes of institutionalisation and professionalisation within four main areas of public musical life: the music press market, concert life, performers, and audiences. The actions of individuals and institutions are also studied in order to highlight the priorities and proclivities underlying the identified changes to public musical life. The period in question saw the transition of concert life from representational culture to the bourgeois public sphere, as well as the gradual division between ‘classical’ and ‘popular’ musical spheres. The study shows that public musical life emerged and expanded within the bourgeois public sphere. Therefore, the ideas and demands of the bourgeoisie were crucial to structural transformation of Stockholm’s public musical life. The old Royal institutions still constituted the core of the public musical life but were adapted to the new bourgeois society. The process of institutionalisation within the musical life was characterized by organisational functions, but also by social institutionalisation of practices within the four main areas mentioned above. The bourgeois ideas of musical Bildung played a significant role in the processes of institutionalisation and professionalization, as it illuminates the priorities and proclivities underlying this process. Several aspects of this development are related to influences from early nineteenth-century musical idealism. The structural transformation of public musical life in Stockholm during the period 1840–1890 laid the foundation for the further developments in the 20th century, and its impact is in some respects evident still today.