The Prague-based ensemble Cappella Mariana was in residence at the Alamire Foundation as part of the Voices of Passion festival. Besides work sessions on little known Franco-Flemish polyphony with experts, an intensive lab session took place in the Library of Voices. This innovative and high-tech session in the Alamire Sound Lab focused on the relationship between the musical source, the performance and the historical spaces in which the polyphonic music, as notated in the source, originally sounded.

Since many of these buildings no longer exist today or have undergone serious changes over time, this research can only be carried out using innovative auralisation techniques. This is a set of techniques used to make live sounds or recordings behave as they would in a particular real or virtual space.

The acoustics of the beautiful Nassau Chapel in Brussels (KBR) were recently measured by the ESAT engineering team and were implemented in the Alamire Interactive Sound Lab during the session. These specific acoustics were then added in 'real time' as an extra auditory layer to the live voices. The result is a form of 'augmented reality' in the auditory domain.

The involvement of Cappella Mariana in the practice-based research provides essential information about the performance praxis within the virtual acoustics of the Nassau Chapel. This is an important step in its further implementation.