This Visigothic altar evokes past periods in which song was vital to liturgical celebrations, since they contained prayers that had been transformed into music. The teaching of liturgical music during these centuries was exclusively via the oral tradition and only after many years of apprenticeship did cantors manage to fully comprehend it. Indeed, Saint Isidore of Seville, a Visigothic wise man, was already conscious of the fact that “the sounds would be lost because they could not be written down.”
In the 9th century, a momentous occurrence took place: polyphony emerged and various voices layered upon each other gave rise to different simultaneous melodies within the same piece of music. This practice brought about the appearance of musical writing or notation that allowed for each of the various melodies to be identified. For the first time in history, it was possible to perform a musical work without having listened to it beforehand. Mozarabic culture inherited and perpetuated this Visigothic tradition. Thanks to this fact, we have been able to preserve thousands of Visigoth-Mozarabic liturgical songs, the so-called Hispanic liturgy, whose peculiar notation system has yet to be deciphered, leaving us unaware of how to properly perform them.