Mythbusters: Religion and Religious Activities at SCA events
You are not allowed to perform religious activities or perform religious music at an SCA event.
The Bust: I have recently heard this old myth at a recent party and I thought I'd combine two for the price of one this month. In the past, there has been a misconception that the SCA does not allow religious activities during SCA events. This is not the case.
Your rights to say practice your religion are a part of your Civil and Political rights and are protected by the International Covenant on Civil and Political Rights (ICCPR) article 18
1. Everyone shall have the right to freedom of thought, conscience and religion. This right shall include freedom to have or adopt a religion or belief of his choice, and freedom, either individually or in community with others and in public or private, to manifest his religion or belief in worship, observance, practice and teaching.
In the same vein, your rights to not be forced into religious activities are protected by the same covenant:
2. No one shall be subject to coercion which shall impair his freedom to have or adopt a religion of his belief or choice.
What does Corpora say?
The Corpora of the Society for Creative Anachronism, Inc. April 7, 2006 revision
II. EVENTS F. Policy on Religion
Having no wish to recreate the religious conflicts of the period under study, the Society shall neither establish nor prohibit any system of belief among its members. No one shall perform any religious or magical ceremony at a Society event (or in association with the name of the Society) in such a way as to imply that the ceremony is authorized, sponsored, or promulgated by the Society or to force anyone at a Society event, by direct or indirect pressure, to observe or join the ceremony. However, this provision is in no way intended to discourage the study of historical belief systems and their effects on the development of Western culture.
Except as provided herein, neither the Society nor any member acting in its name or that of any of its parts shall interfere with any person's lawful ceremonies, nor shall any member discriminate against another upon grounds related to either’s system of belief.
What does this mean?
The SCA is very clear that it cannot be involved in it's official capacity.
If you are holding a mass or a religious ceremony at an event, you can advertise it however it cannot be advertised in a way that would suggest that it's an official part of the event. EG. “Mass will be available to those who are interested at 10am at <x location>. This is not an official part of the event”. No-one can stop you from holding a mass, praying or holding a special ceremony or having a private reading. Just be courteous about it and don’t force people into a situation where they will feel uncomfortable.
But what about religious music?
Go for it! I recommend Palestrina, Byrd and Tomas Luis de Victoria.