Music and the passions were of as much interest to religious thinkers as they were to physicians. In his eloquent reflections on the nature of spirituality and music, Cobusson speaks of music as occupying a liminal space in which all assured and secure structures and boundaries of our existence are undermined. It is neither subject nor object but an ‘inbetweenness’ connecting body and soul, the divine and the human; a threshold that by definition is neither one thing nor the other, and therein lies its power or efficacy. The proximity of body, mind and soul is reflected in religious writings concerning the passions and music's capacity to act on them. These concerns are already evident in the late antique sources documenting the history of the Christian Church in the east and in the west.

Music in the Christian liturgy in the form of recitation, chanting and singing evolved in the same Christian societies of late antiquity responsible for the emergence of the hospital. The divisions between Christians who chose isolation in desert communities to focus on their own spirituality and those who set up monasteries in urban areas to minister to the local population are reflected in different rules of monastic living, expressed most clearly by the enclosed work of prayer of the Benedictines and the community-focused Augustinians. Viewed in this way, monasteries and hospitals are twins. The historical development of the hospital runs parallel with the development of the monastic Offices, and this close relationship between religion and medicine is entwined with music. Those ministering to the sick were also committed to a life of constant prayer and psalm singing.

The passions in religious thought

Late antique sources written by the Church Fathers active in the fourth century, such as Jerome, Basil of Caesarea, Augustine and Gregory of Nyssa were core to early modern religious education and therefore to the men who ran and worked in the Hospital of Santo Spirito. Many of these antique sources mention music in general terms, and psalmody in particular, and it is clear that the psalms, unlike readings, were sung. These sources also note the regularity of singing and its beauty, demonstrating an appreciation of the rhetorical power of psalm-ody and the ability of psalm singing to control the passions.