At the (Oz) National Folk Festival, every Easter, Sunday morning is the occasion for a Hymn Singing session, scheduled to occur at the same time as the Poets' Breakfast and the judging of the new dances in the TSDAV Dance Competition.

I'm sure there are a few believers there but I can assure you that many of those who lead the singing are atheists/agnostics/non-believers. Some years ago a few preachifiers sought to proselytise but were politely asked to take their proselytising elsewhere, as this was a singing session where love of harmonies was paramount.

Cheers, Rowan