I live downtown and walk by The Midland Theatre most days. On some evenings I see a line of patrons waiting to get in. Without looking at the ornate marquee, I try to solve the mystery of the event. Are they half-dressed kids in furry raver boots? Are they greyed boomers in golf shirts? My observations feed my guess, and then check my answer. Anyone playing this game on Friday night was in for a treat. Studying the line that encircled an entire city block, our amateur contestant probably thought the show was some sort of metal affair. Black boots, black jeans, black shirts. Makes sense. However, a particularly attuned observer may have noted the preponderance of runes printed on those black concert shirts or seen the faces in the crowd either smudged with earth or decorated by thin geometric lines. Smugly our master sleuth might confidently declare that it not only metal, but specifically Viking metal. Even medieval tunics and primitive pelts seen in the crowd surely support our confident detective's conclusion. And for that I would give them half credit because it would take a subculture-embedded version of Hercule Poirot to surmise that this combination of renaissance faire cosplay, pre-Christian Germanic shamanism, and modern pagan metal was not the trappings of a metal concert at all, but instead the gathering of a tribe preparing to see Danish folk interpreters, Heilung. I, of course, knew this immediately, but only because I was waiting in that line. But even with that mystery solved, the night still held its secrets – ones I will not reveal. But I can provide hints on what happened when the doors closed:

Thinking of Heilung as a band isn't useful. Of course, there is music performed by musicians. In Heilung those core musicians are vocalists Kai Uwe Faust and Maria Franz, and multi-instrumentalist producer Christopher Juul. Heilung's sound is also augmented by another handful of percussionists and vocalists added for the tour. Together the assemblage creates pieces that may be long and hypnotic or short and sharp. They use animal skin drums, bones and antlers, rattles, and droning instruments, but mostly they use their voices – wild vocals, four-part harmonies, throat singing, beautiful voices and frightening ones. In the extreme, some pieces are purely literary, consisting of long sagas shared in dead languages over minimalist accompaniment. But the band insists that they don't play songs, they perform rituals. I'll admit the distinction is often lost when merely listening to an album. Live, however, the ostentatious assertion is mostly warranted.

And that leads to our second hint, Heilung is a performance. It's both epic and operatic. There are sets and costumes and scenes and choreography and lighting cues. Dozens of shirtless warriors, smeared with ashes, brandishing shields and spears join the musicians on stage, amplify the band's message, marching, chanting, shouting, stomping, and dancing exuberantly. Like most operas I've attended, I often had no idea what was going on. Was that a sacrifice? A murder? A rescue? A resurrection? There are some secrets of the show that I cannot share with you because I don't know the answers myself.

Finally, the last hint. The biggest secrets of the show are actually unknowable. With its performance, Heilung calls to the oldest and biggest mystery there is – God. Each of Heilung's core members embrace a pre-Christian religion of ancient and animistic Gods. Historical sources dating from the Iron Age to the Early Middle Age not only create the rites and rituals of their neo-pagan religion, but also serve as lyrics for much of the band's material. Using this knowledge, the band channels the past, serving as storytellers and shamanistic guides for its receptive modern audience. It began with the opening ritual, repeated by both bands and fans:

Remember that we all are brothers
All people
And beasts and trees
And stone and wind
We all descend from the one great being
That was always there
Before people lived and named it
Before the first seeds sprouted

One hundred and twenty-six minutes later, when the corresponding closing ceremony was complete, the audience was changed. Were we to thank the ancients? Healing rhythms? The smudging ceremony? Faust's incantations? I'm not sure, but I suspect solving that mystery is beyond even the powers of our extra-fictional Hercule Poirot.