This research undertakes an interdisciplinary investigation that combines medieval musicology and virtual acoustics applied to heritage spaces. It is centred around acoustic reconstructions of the Great Chapel within the Palais des Papes in Avignon during various historical periods. This chapel served as a significant venue for choir singing of the Ars Nova musical repertoire in the 14 th century, coinciding with the Palais des Papes' role as the official residence of the papacy. The study presents a concise overview of the architectural history of the Palais des Papes and its chapels, followed by the methodology for virtually reconstructing the acoustics of the Great Chapel under diverse conditions. An experimental phase employed a choir ensemble specialising in the Ars Nova repertoire, immersing singers in the virtual acoustics of the Great Chapel using a real-time room auralisation system designed for headphone reproduction. Through this experiment, we examined the singers' musical performance in response to the simulated acoustics. The efficacy of the proposed auralisation system was assessed based on participants' feedback regarding its ability to accurately replicate the acoustic conditions of an authentic music performance space.