It's uncomfortable straddling the fence on this issue. I'm right up there with Marje's comment:

"I really don't see how either of the extreme positions ("no one has a right to join in a song with another person unless explicitly invited"; or "anyone should feel free to join in with another singer unless asked not to") could be made to apply to all situations."

Perzactly. And I tend to love most of all the performers and groups who mix it up in a concert, so that in a set there might be the entire gamut of:--Hush up and listen to this hair raising ballad--sing along on this old chestnut everyone knows --join in on this chorus--tap your feet to this jig, but we might change time signature on you--Song you know, but played in a whole different way. Perhaps these are performers for a sophisticated audience who can take a hint about when to sing and when to not?

I think of other audiences whose previous concert experiences were in the vein of Pete Seeger or Clancy & Makem, where singing along was nigh onto mandatory. Or they're rabid fans of a particular artist and know every word and nuance - of the original - and think their love of the song necessitates their joining in, even when it's another performer doing the song, in a different style or phrasing. I've BEEN these people. And then been sensible enough to pick up the cues from the audience of what is appropriate to THAT concert. Folk music tends to draw a fair number of people whose social skills will never attain that, and sometimes need to be told, repeately. Kindly, but repeatedly. A good performer can do that telling in a subtle way. I truly wonder how much of the rudeness of singing along inappropriately springs from the current culture of uninhibited cellphone conversations in vastly inappropriate places and situations?

In non concert singing sessions I find myself vastly annoyed by the trend toward sessions where every song is expected to be something every one can sing and play on, precluding learning new songs, (or not doing anything that isn't in the "blue book" ) I want to smack the dorks who don't understand the concept of acapella "but, I can tell what the chords are!" I so miss being part of sessions that were a mix of singing along, singing choruses, listening, being bored and wandering off for a drink, being astonished at someone's brilliance or enraptured by a new song.

I figure you cherish the times when you are in a singing or listening situation where everyone is on the same wavelength about who is singing and why & do what you can to make those happen more often than not.

Joanne in Cleveland