This dissertation explores the active roles of ritual music known as xochitl sones (flower-musical pieces) or sones de costumbre (musical pieces of the tradition), in the context of la costumbre Nahua religion of eastern Mexico. This multi-sited research is based on twelve months of ethnomusicological research conducted in 2010-2011 among several Nahua towns in the municipality of Chicontepec, Veracruz. The main focus of research is the town of Ixcacuatitla located at the foothill of the Postectli Mountain, an active ceremonial center for Nahua, Otomi, and Tepehua ethnic groups. By primarily looking at conceptualizations concerning the chicomexochitl ceremony offered to mountains, this study shows how ritual music articulates participation and emotional engagement in order to bring the rainfall that is essential for agricultural production. The musical repertoire consists of about 150 musical pieces that are arranged according to the events, actions, and deities represented in the ceremony. The characteristics of the musical elements and the large structure of pieces paralleling the events configures the engagement of the participating audiences in the performance of the ceremony. Over a period of days, congregations and dedicated ritual specialists gather to prepare and present large amounts of offerings including food and animal sacrifices. While all engage in the different activities, dancing together to the rhythm of the violin, jarana and huapanguera is one of the most representative aspects of participation, where emotions such as weeping and joy are offered to the Chicomexochitl deity. This dissertation argues that the relevance of music and dance in articulating such emotional involvement directly corresponds to the value attributed to participation in the system of communal reciprocity, which is a basic principle of socialization in these Nahua towns and further enables an interaction with the sacred landscape.