It is traditional to sing this one song at Latvian weddings, it is sort of their “song of the open road” if you will. Also, Latvian weddings are usually three day celebrations.
The song (or “daina”) that my family sang at my brother Alex’s wedding was the first time I had heard it(I hadn’t been to any Latvian weddings before that). It is called ??rbies, saule sudrabota, “. I dont know an English translation for it, sorry. As for the three day party that ensues, that is something that I first learned about also at my brother’s wedding, but as far as I am aware, that’s a very northern European thing to do; I think the Swedes are all about that. -Kate P.
The English translation of the title is Sun, Clothe Yourself in Silver. I couldnt find the lyrics to the song, or the English translation, but it sounds as those it is almost a song wishing him good luck as he moves onto the next part of his life.
To address the three day wedding ceremony, in the International Folkloristics by Dundes, there is a chapter by Geza Roheim that talks about many interesting European wedding traditions. The ancient wedding festival could last for weeks so this seems to be a natural, modern evolution of those festivals.
To reference in text:
Straumanis, Alfreds. The Golden Steed: Seven Baltic Plays. Long Grove, IL: Waveland Press, 1979. Pg. 180