The reformer Martin Luther, a prolific hymnodist, regarded music and especially hymns in German as important means for the development of faith. Luther wrote songs for occasions of the liturgical year (Advent, Christmas, Purification, Epiphany, Easter, Pentecost, Trinity), hymns on topics of the catechism (Ten Commandments, Lord's Prayer, creed, baptism, confession, Eucharist), paraphrases of psalms, and other songs. Whenever Luther went out from pre-existing texts, here listed as "text source" (bible, Latin and German hymns), he widely expanded, transformed and personally interpreted them.