This paper examines the links between the musician Giovanni Battista da Gagliano and the Compagnia di San Benedetto Bianco in Florence, a religious confraternity to which he belonged. Given that the confraternity's defining feature was a penitential form of spirituality, it seems plausible that the spiritual compositions included in Gagliano's Varie musiche (1623), about the death of Christ and the planctus Mariae were originally composed for this setting; or that Gagliano was inspired to write them by his association with it. In the seventeenth century, several paintings were made for the interiors of San Benedetto Bianco by prominent Florentine artists (many of whom were also members of the confraternity). The imagery in these paintings depicted the key events of the Passion, to inspire spiritual and corporeal mortification in the confraternity members; similarly, Gagliano's penitential pieces of music may have been intended to produce, through meditative lyrics and gloomy melodic lines, the same emotions felt by Christ or by the Virgin at the foot of the cross. With the support of various spiritual texts used at San Benedetto Bianco, and on the basis of some significant textual similarities and convergences between texts and imagery, the author theorises that there was a relationship between the musical dimension and the painted representations, attempting to understand if and how the aural component interacted with the visual one during ritual practices. This 'synaesthetic' fusion made such moments more impactful, by rendering them multi-sensory experiences in which both art forms contributed to increasing the confraternity members' sense of involvement and propensity for contemplation. Furthermore, several manuscripts held at the small archive at San Benedetto Bianco, situated within the Parish Church of Santa Lucia sul Prato, Florence (the confraternity's final premises) were examined; they revealed that one of Gagliano's pieces included in the 1623 print, Ecco ch'io verso il sangue, was sung at the confraternity as part of a sort of theatrical performance on the evening of Good Friday, following the moment when the members usually carried out flagellation. [ABSTRACT FROM AUTHOR]