I have just come across this initiative by Gareth Malone of BBC fame.
if you click on the link above it will take you to a registration site where you can join in his Sing at home sessions. That is all I know. Apparently someone saw him on tv this morning talking about it. I presume it is free.
there is also another group called the sofa singers.
 link is https:// www.thesofasingers.net 
they are next "meeting" at 7.30 on Friday evening. You will need to download zoom to join in. 
I am not taking commission from any of these sites. But will see if I can log in and then report back on my experience. 
Dave
ps our old friend Seb is running his choir online but is also offering free lessons in using Sibelius which helps you arrange and compose music. The link can be found on our Facebook page if you are interested.