Thank you very much, Max well. This is one of my favorite nigunim, and the video brought me to tears, between the beautiful music, the meaningful lyrics, and of course, the view of Yerushalayim Hakedosha.
Shavuos piyut it may be, but the first few lines were popularized by Yiddle Werdiger (who has a good voice and often fantastic arrangements). The lyrics are probably in the liner notes.