I agree, we need to keep this discussion to sessions, but there are plenty of mixed sessions in the UK, with mostly tunes and occasional songs. The one I run in Totnes is one of them, and the other sessions I attend regularly also have a mix of songs and tunes. Some evenings it's all tunes, but most often there are a few songs in the mix. I'm not talking about round-the-room singarounds, they're just open pub sessions where anyone who wants to start a song can do so.

It would be very odd if a singer started a song and had to be interrupted to be told it was not in any of the accepted keys.A guitarist, for example, might choose to play and sing in Eb (with or without capo) because it was the right pitch for his voice and that song - or possibly even because he didn't want melodeons and pipes joining in. And an unaccompanied singer will often not know what key he's chosen, he'll just pick a note out of the air and start to sing. Dictating the agreed keys for the evening in advance would rule out such singers.

Marje