The musical notation of the northern Italian Benedictine abbey of St Sylvester in Nonantola has hitherto been neglected by most scholarship on early music scripts, mainly because of the paucity of surviving music manuscripts and their limited geographical diffusion. A new study was needed in order to develop a full understanding of the abbey’s role and importance in the first phases of development of the writing of music in the early Middle Ages. A Lombard foundation, Nonantola acquired much of its prestige from the links with the Carolingian court as early as the late eighth century. From the first decades after its foundation, the Po Valley abbey also benefited from an active scriptorium; this shaped a local type of text script that endured until after the fall of the Carolingian empire, when the abbey, including most of its library, was destroyed by the Hungarian invasion in 899 (§1). The study of the earliest surviving notated liturgical manuscripts revealed that, by the late ninth century, Nonantola already developed an institutional type of musical notation, making it the earliest known music script ever to be written in the Italic peninsula and, thus, among the earliest in Carolingian Europe (§§2–3). The unique design and use of musical signs showed that this northern Italic notation developed, for the most part, independently from a basic repertory of graphs derived from grammatical accents (§4). Finally, observations of the influences of the central Italic nota romana, which this study only began to explore, opened up the possibility that Nonantolan notation may preserve the oldest traces of graphic conventions for the representation of sound that can be associated with the city of Rome (§5). Placed between the northern and southern fringes of the Carolingian empire, the Benedictine abbey of Nonantola played an important role in the early history of music writing, and this study contributes to the breaking of new ground for further explorations.