Southern Comfort has already kindly added some comments on the latest position. However, having just finished wading through the latest legislation and the Guidelines issued today (which are appallingly drafted!), I thought that it might be helpful to start a new thread covering all of the latest changes.
In relation to singing, the rules have been widened (as SC has said), and now also conform with the Performing Arts Guidelines - so that we can now have choral groups comprising several gatherings of 6 (providing the groups of 6 cannot mingle with each other). In addition, the usual rules about social distancing apply between the groups of 6 and within the groups of 6 (except for people in the same households, bubbles etc).
However, subject to following the Performing Arts Guidelines, there appear to be no restrictions on groups of professionals or of groups of supervised under 18's. I think it must follow that a group combining professional adults and supervised under 18's should be treated in the same way.
In relation to 'lifetime events' (baptism, weddings, funerals etc), the changes only come into effect on 28th September. Until then the law and Guidelines operate as before. On and from 28th September, funerals remain limited to 30 people, weddings become limited to 15 people and all other 'lifetime events' are limited to a group of 6. 'Workers' at such events are not included (this is not defined, but seems to include celebrants, readers, others who assist in the conduct of the ceremony and stewards). In addition, however, there has been a change of language so that where the 'lifetime event' is not a funeral or wedding and is an element of a service of communal worship, the guidelines for communal worship apply. The current exception for weddings and funerals that take place as part of a 'routine act of communal worship' will no longer apply. In addition, there are separate Guidelines for small weddings and funerals that also apply (but are not significantly different to those contained in the main 'Religious Worship' Guidelines.
There are a few other minor 'tweaks' to the Guidelines, but I don't think that they make any material difference to the current position. However, I think that there are a number of errors (both of principle and in the drafting) which may well have to be fixed by further updating in the near future!
The Government's Guidelines for Public Worship III - the changes on and from 24th and 28th September
Moderators: Dom Perignon, Casimir