Here are some verses of a hymn from the "Service Book and Hymnal of the Lutheran Church in America" (1958) It is interesting how it combines references to the return of the sun with the coming of Christ. The words are by Laurentius Laurenti, 1660-1722. I guess he was Swedish, because the melody is a Swedish folk tune.

Rejoice, all ye believers, and let your lights appear
The evening is advancing and darker night is near
The Bridegroom is arising, and soon he draweth nigh
Up, pray, and watch and wrestle, at midnight comes the cry!

The watchers on the mountain proclaim the Bridegroom near
Go meet him as he cometh with hallelujahs clear
The marriage feast is waiting, the gates wide open stand
Up, up,ye heirs of glory, the Bridegroom is at hand!

Our hope and expectation, O Jesus, now appear
Arise, thou Sun so longed for o'er this benighted sphere
With hearts and hands uplifted, we plead O Lord, to see
The day of earth's redemption that brings us unto thee!

(Before anybody gets sarcastic, yes,I know that the reference to a Bridegroom is to the parable of the wise and foolish virgins.)

Anyway, if you are having a solstice party, you can set this to a little march tune and use it.