Each New Year’s Eve in Appenzell, Switzerland, groups of oddly bedazzled men gather for an arcane ritual of polyphonic yodelling and rhythmic bell-clanging. No one knows how or why it began.

This wonderfully surreal, sometimes sinister work from art-world provocateur Andrew Norman Wilson takes us high into the Swiss Alps and to a mysterious pageant that dates back some 500 years, in which ornate costumes, cryptic utterances and hypnotically absurd chants commune – a portrait of strange, occult-world beauty.