I chose the Nunc Dimittis or "Song of Simeon" as the song that calms me. I sing this song after receiving Christ's body and blood in the Lord's Supper. Originally, the petition to "let thy servant go it peace" was meant by Simeon for God to allow his earthly life to end, as he had just seen and touched the promised Infant Christ. However, it is just as applicable a petition for communicants who most certainly did not enter God's house in "peace", but in sin and misery, to now leave with the peace of forgiveness, having also heard, seen, and touched Christ, as well as being united with the whole Company of Saints who have fallen asleep before us and are awaiting the resurrection.
Lord, now lettest thou thy servant depart in peace, according to thy word.
For mine eyes have seen thy salvation which thou hast prepared before the face of all people,
A light to lighten the Gentiles, and the glory of thy people Israel.
Glory be to the Father, and to the Son, and to the Holy Ghost.
As it was in the beginning, is now, and ever shall be, world without end. Amen.
The profundity of this weekly experience cannot be overstated. So frequently have I bowed my head at the altar, not out of piety, but to hide the tears that inevitable spring to my eyes as I am overwhelmed by the seemingly paradoxical emotions of sorrow and gratitude, longing and relief, humiliation and elevation. When I sing "The Song of Simeon", I am at peace again, like an inconsolable infant who has just been nursed by her mother.
That analogy is more true than it seems, as I actual prayed this prayer in my mother's womb, when she (and perhaps I?) received the Sacrament, as she did with her mother. Prior to my grandmother's generation, the language and music would have been different, but many generations prior have sung Simeon's song. Children continue to sing it today, as seen in this video of a recent Lutheran youth conference.
Liturgical pieces like the Nunc Dimittis span time, space, language, and even denomination. They are a deeply-ingrained part of not only my own family's culture, but many other cultures as well. This is part of the calming effect of this music. It unites one with so many, bridging the expanses of time, space, and even physical death. It has a way of shrinking one's problems into insignificance, shortening one's suffering with a widened perspective, alleviating loneliness with universality, and removing the self-absorbed "blinders" from one's heart and mind.
I found this music challenge on the blog of 
