The degung is a small game lan that is unique to the Sundanese people of West Java. Originating as a prestigious ensemble for the local nobility and formerly confined to the region's administrative courts, the provincial capital city of Bandung has been the geographic focus for the degung tradition since the first decades of the 20'h century. Following sixteen months of fieldwork in Bandung, the dissertation examines the evolution of the gamelan degung in the musical melting pot of this bustling urban centre. Situating the ensemble within the heterogeneous landscape of Bandung's regional arts scene, it considers the way in which degung has come to be positioned as a musical 'common ground' for performers hailing from a variety of socio-cultural and musical backgrounds, as well as a site for the negotiation and assimilation of repertoires and performance practices drawn from across the wider Sundanese music complex. Central to this investigation is the theme of musical transformation, a topic that is explored from several interrelated perspectives. Piecing together a history of the ensemble, the study correlates musical innovations to socio-cultural, politico-economic and technological developments, as well as to broader shifts in Sundanese music as a whole. Specific attention is paid to the ongoing popularisation of degung by the local cassette industry and the role that 'invented' ceremonials have played in the ensemble's postcolonial renaissance. Interweaved into this chronological survey are more focused analyses of the core and specialist skills of the musicians and the intrinsic malleability of the music systems that lie at the heart of such musical change. Transformation is identified as a primary domain of Sundanese musical competence, with processes of transfer and adaptation shown to permeate the creation and realisation of degung repertoires. These diachronic and synchronic accounts of musical transformation are considered to complement rather than to contrast with one another; it is argued that the manner in which the degung has adapted to its altering 'external' environment over time has been determined, at least in part, by the essential constitution and 'internal' dynamics of the larger musical culture in which the ensemble is rooted.