One of the things I enjoy about sessions, or even more formal settings, is the sort of atmosphere where you find that people have to be forced to go home at the end of the event because they're so busy talking to each other. Let's not forget that song & music are ways of connecting with each other & some will respond to certain things but not others. So really I'm pretty tolerant as long as whatever is sung and or played contributes to an overall feeling of wellbeing. It would be a shame if people went home feeling that they'd heard some good music - however defined - but ended up feeling lonely & left out of things. Because we all lose if that happens.