Lacunae Ciconiae aims at reconstructing missing voices in the oeuvre of the composer Johannes Ciconia (ca.1371-1412) and musicians of his circle. Several compositions either securely attributed to Ciconia, or having a close affinity with his style, survive only in damaged sources and have come down to us not as complete works, but as fragments. Fragmentary music tends to be neglected by researchers and performers, because of the problems posed by music that is either incomplete or has become illegible to the naked eye. This project focuses on the reconstruction of this fragmentary music, using hybrid intelligence to propose performable editions of a number of pieces and re-evaluating their place in Ciconia’s oeuvre. The current phase of Lacunae Ciconiae builds on earlier results obtained by the project, employing state-of-the-art imaging technology, and developing new tools of digital musical analysis, specifically to investigate this repertoire. In the semi-oral culture of polyphonic music-making at the turn of the fifteenth century, the compositional process cannot satisfactorily be investigated without regard for the oral transmission and mental components of composition and improvisation. A small-scale 'living lab' (working title: LacunaLab) will conduct practical experiments in these areas.