Wonderful Mystery is a collection of seven Christmas carols for choir and instrumental accompaniment (harp or piano), whereby the music has a completely new setting. The basis of all seven pieces are English Christmas texts from the 15th and 16th centuries. When composing, Jan Wilke orientated himself on traditional models of Anglican church music; for example, the first verses are often solo or in unisono or, in the last verse, a crowning upper voice. It was important to him to convey the emotionality of these timeless texts as well as an easy execution.
Although the choral edition includes the harp/piano part besides the vocals, the compact version of the instrumental part is available in this edition.