I came across this video on YouTube while searching for something else entirely. "The Alter Rebbe's niggun is the most sacred of all Chabad melodies," reads the description, "and is only sung during weddings and other special occasions." One might think, judging by YouTube content, that niggunim are popular only in the Orthodox and Hassidic words. This was once the case, but they are now sung, traditionally as wordless melodies or set to prayer, by all streams of Judaism. To me they sound like a direct conduit to the past, and a mystical world no one understands anymore. I have before never heard one played on the flute, as in the haunting and beautiful example below. The musician is praying, not performing; it's impossible to listen without closing your eyes and remembering that Shabbat will be here very, very soon.