The Christian tradition’s liturgical repertoire prominently features Masses and Offices commemorating the life of Christ and feast days of saints. Alongside this, another significant repertoire revolves around Christ and the saints through their relics, which are venerated as physical representations of divine presence. These relics vary in significance, with those tied directly to Christ holding the highest status, followed by those connected to the Virgin Mary, John the Baptist, Apostles, and holy martyrs. A notable private collection of relics belonged to the Byzantine Emperor until 1204, when it was mostly acquired by Louis IX of France, who constructed the Sainte-Chapelle in Paris to house them. Similarly, in the Kingdom of Aragon, relics were venerated in a royal context, with a collection established during the reign of Martin I. This collection included fragments of the Holy Cross, the Holy Grail, and relics of Saint George, which were later deposited in the cathedral of Valencia. This presentation of relics was not only a spiritual practice but also integrated into religious ceremonies, often accompanied by hymns and prayers. Many of these relic-based traditions have been preserved in manuscripts that reflect medieval spirituality, offering a glimpse into the deep connection between relics, music, and devotion. The music associated with these relics, though little known today, is a rich part of the medieval cultural and religious legacy.