Medieval literature is full of tales in which miraculous goings-on coincide with the audition or performance of song. Precedents go back to antiquity and the Bible, yet from the moment that Romano-Frankish chant was established as the musical lingua franca of Western Christendom, in the ninth century, many authors began to weave their tales around named or otherwise readily identifiable compositions. Very often the text of the chant can explain (away) the allusion. Equally, as Christopher Page has pointed out, music that was liturgically positioned had a unique propensity to serve as a "coordinate" in the collective memory of an event (2010, 2016). 

However, closer examination of these stories reveals that some musical scenarios were more highly favoured than others, suggesting that that there is more to these citations than meets the eye. Liturgically-inclined scholars have already observed as much, albeit obliquely. Writing about the visionary Elisabeth of Schönau, Felix Heinzer noted the potential for vision narratives to be aligned with "dramatically accentuated moments" of the liturgy, in which category he included the dramatic unfolding of the responsory chant (2013). Meanwhile, Éric Palazzo has noted how liturgically-induced visions tended to cluster at night, during the musically-intense night office of matins (2010). 

In this paper I draw these strands together by exploring a significant, yet hitherto unnoticed, concentration of miracle stories that coincide with matins responsories, specifically the extended responsory performances that marked the ends of nocturns. Whilst many of these narratives appear to reference wordless ‘neuma’ melodies, famously allegorised by Amalarius of Metz as marking a threshold between human and divine, this is not the common theme. Rather, the unifying strand is the concept of the threshold. Experienced ritually yet understood eschatologically, the notion of "crossing over" was articulated simultaneously by the ritual action, by the musical content, and by the layered narratives of chant texts, liturgical texts, and hagiography. Amongst the implications of these observations are fresh insights into the design of chants in saints' historiae, as well as a reconsideration of neumatizing and polyphonizing as performance practices within the medieval Divine Office.