Reading and viewing twentieth-century Irish drama means repeatedly encountering Irish songs and traditional musical instruments. While music is an element in most theatre performance, Irish Traditional Music (ITM) figures centrally in much Irish theatre, signaling the cultural and ideological weight of ITM and its production in Irish cultural expression onstage. This dissertation posits that understanding the cultural matrices, traditional music trends, and theatrical tropes that intersected at specific moments in Ireland’s twentieth century will necessarily enrich both the scholarly analysis and embodied performance of Irish dramatic texts that feature musical instruments. To analyze such intersections, the project isolates and examines three periods during which multiple playwrights used traditional musical instruments as onstage icons, properties, and discursive tools. Following the material turn in both theatre and music histories, the paper urges the reading of musical instruments in Irish plays as essential theatrical objects carrying discrete and evolving meanings from the cottages, Céilís, and pubs in which they socially functioned onto dramatic stages. The dissertation thus reads what meanings musical instruments carried into original playhouses in order to develop a more nuanced understanding of both how plays work on their original terms and how dramaturgs may approach past texts with an eye towards respecting and recreating their original resonances.