For those not deterred by network latency, Making Music has put up a page of suggestions[1]. (Making Music is a UK-based organisation that provides information, advice, advocacy and various other services for amateur music groups)
[1] https://www.makingmusic.org.uk/resource/covid-19-staying-connected?utm_source=Solus&utm_medium=Email&utm_campaign=iNotesMar2020
