In December 2015, a previously unknown and exceptionally well-preserved music manuscript was discovered by chance: the 'Leuven Chansonnier”. Quickly, it became apparent that this little chansonnier had been the most significant source discovery for secular music from the latter half of the 15th century in more than 75 years. Now, almost a decade later, many of its facets still leave musicologists perplexed. My research proposal involves detailed study of this chansonnier and the sources most closely related to it: the five 'Loire Valley' chansonniers. Through the combination of (musical) stylometry, statistics and artificial intelligence, a computational and style-based approach will be taken to provide new insights into the contextualisation of their repertoires. This approach will additionally provide new arguments for possible composers of the Leuven Chansonnier's pieces through a new and statistically backed characterisation of their compositional styles. The resulting contextualisation of the Leuven Chansonnier and its five related chansonniers will sharpen modern understanding of musical life in the late medieval period. Additionally, style analysis of their pieces will strengthen and deepen scholarly understanding of their music and its composers.