The Lutheran Reformation gradually reformed liturgical music and the style in which it was performed, revealed by vernacular languages beginning to be sung in church services in addition to Latin. This gave the congregation – at least in principle – the possibility of participating in singing (see Ross in this volume). The change was not radical, however, nor was it particularly quick, and church services initially retained much music in Latin. It was also a significant innovation that metric and rhymed songs began to be written. For the congregation, those songs were easier to sing together than the old prosaic hymns. One song that was both preserved and reformed was the age-old hymn Te Deum, which has been the most famous liturgical song in the Western Church. It has appeared in a variety of translations in different languages alongside its Latin form.

This study ascertains the number of different Finnish translations of Te Deum in 16th- and 17th-century music manuscripts and in the earliest Finnish books. It also examines the interrelationship between the translations, their dates of translation, and the influence of the source languages on the translations. While it is unknown whether there were any Finnish translations of Te Deum as early as the Middle Ages, certain features of the earliest translations suggest that they are relatively old.