Someone has to be in charge. In the US, it is rare to find someone who sings that doesn't play an insturment.
    Here in bluegrass country, we have another problem. EVERYONE wants to take breaks on the song, doing something with their insturment. The problem occurs when you have fifteen people wanting to take breaks on a song. Something like "Mama Don't allow" lets people perform, but it's no fun for the person who wants to actually sing a song unaccompanied. If you try to play something like John henry, you'll be there all night!!!
    Whoever is in charge needs to be sensitive, considerate, encouraging, and fair.