Michael Praetorius was one of the most prolific and innovative Lutheran composers of the early seventeenth century. His Megalynodia Sionia ("The Magnificats of Zion") is a collection of fourteen Magnificats for use in Vespers services. The compositions in the collection present a series of complicated issues that modern editors and performers must unravel to be able to perform this music. The most common method for performing Magnificats at this time was alternatim, in which different musical groups alternated in performing verses. For eleven of the Magnificats in Megalynodia, only six of the twelve verses are supplied by Praetorius. Appropriate sources for the other verses must be identified. Also, there was a tradition in the Lutheran church of inserting chorales between the verses of the Magnificat on feast days. The chorales would be songs associated with the occasion, for example Christmas or Easter. Praetorius gives important instructions to prospective performers as to how these insertions should be chosen and performed. Eleven of the Magnificats are parodies of works by other composers, Orlando di Lasso in particular. Parody technique is the use of polyphonic music by another composer as source material for a new composition. It was a very typical compositional method of the sixteenth century. Lasso started a Continental tradition of using parody technique in the Magnificat; in this collection Praetorius follows in his footsteps. One must take all these issues into account in attempting to create modern performing editions of this music. The study culminates in performing editions of two Magnificats from the collection.