This thesis attempts, for the first time, to address a comparative analysis of the role that liturgical music played in the process of building the sacred image of the sovereigns of the Bourbon House of France and Spain as part of the religious ceremonies celebrated in Madrid and Versailles during the last decades of the Ancien Régime, as well as the role that the example of the Pontifical Chapel played in this process. The main purpose of this study was to provide a conceptual framework and analytical model that would allow a global study of sacred music for these ceremonies to be approached from a perspective closer to cultural history than traditional musicology, but always starting from the analysis of the performative aspects that revealed the reciprocal interaction between music and the ceremonial, political and historical context of which it was a part. Along six chapters, we examine the elements that shaped the ceremonies of the State liturgy, conceived at that time as sacred representations: the different scenes in which they took place, the actors, the ceremonial, as well as the functioning of the different styles of singing used to solemnize both the ordinary and extraordinary ceremonies celebrated in Rome, Madrid and Versailles between 1745 and 1789. This included not only sacred music works produced ad hoc by the choirmasters, but also other music, such as plainchant, counterpoint or faux-bourdon, which were sometimes performed by improvisation or memorization as part of this same system of representation.