I think that there is an intersting distinction between performing a song for an audience of people who are knowledgeable and interested in the tradition, and people who just want to hear the song, Dammit! I've heard people over here give an extensive background to a song, boring the Hell out of everyone, because they're not being sensitive to the audience. If you're playing at a gathering where people are just coming to have a good time, you can kill it in a hurry giving an extensive background to the song. A really good traditional song can reach across time and have a contemporary relevance.
An example:
"I woke up one morning in the spring of '65 I thought myself quite lucky to be found alive I geared up my mules, my business to pursue Instead of hauling four loads, I only hauled two
I got so drunk at Harper's I couldn't stand no more The men all telling jokes, I laughed 'till I was sore The fiddler being willing, his arm a-being strong He played the Crippled Kingfisher, about four hours long
Come all you newsy women, who scatter news about Don't tell no tales upon us, we're bad enough without Don't tell no tales upon us, or kick up any fuss You've been guilty of the same thing, perhaps a whole lot worse"
Those are three verses of a much longer song about a bunch of men getting together, having a good time and getting drunk. You could pull our your guitar and play that in any bar in this country with NO introduction and everyone would relate to it.. and get a big kick out of out. A long introduction of the origin of the song, where Harper's was, who recorded it, and who you learned it from would if anything, detract from the enjoyment of the song in some quarters. Sometimes, honoring the tradition is just trusting the song to speak for itself.