I believe two things.

First, as a patron of the arts I’m entitled to certain expectations. If I attended a musical where main characters forgot the lyrics halfway through a song I’d complain afterward.

Second, no member of the audience may make any sound after the curtain rises until it falls again. That time belongs exclusively to the performers, no matter how objectionable their work. Complaints get voiced after a show.

I attended yesterday’s Eddie from Ohio concert in Somerville, where we had the pleasure of a persistent heckler. This group (one of my all-time favorites) is well known for telling stories during their shows. Even on their CDs we can hear their often elaborate introductions to songs. At yesterday’s show, for instance, we were treated to a hilarious ad hoc rendition of the popular Great Day that played on the lyrics being misheard as “Great Dane.” It was so funny that singer Julie Murphy Wells couldn’t go on to the next song; they skipped over it.

This is what live music should be. There’s great joy in hearing music created live on stage, but we also want a small taste of having “met” the performers, so we can step outside their CD and recognize that we’re seeing them in person. When Celtic Woman came to Boston last June they so faithfully executed the over-produced staging they could as effectively have projected their DVD on a movie screen.

One patron at last night’s show disagreed with me. When the group launched into the introduction to one song he shouted, emphatically, “You’re here to sing!”

Well! Are they, now! When they brushed it off he persisted, shouting out again. He was silenced only when bass player Michael Clem drew enthusiastic cheers with his quip, “I hope you’re drunk… because stupid is forever.”

I respect that he just wants to hear the music – our opinions differ, and that’s fine. The difference is I didn’t jump up during Celtic Woman’s performance and shout, “You’re here to talk!” Just because you don’t understand a performance (and the introduction to a song is every bit a part of the performance) doesn’t mean other people don’t. We were all enjoying it.

A heckler at the Blast! performance in Lowell on Thursday similarly seemed to miss the point of the show. It’s very playful, bringing performers out into the audience and showcasing musical battles on stage. In Everybody Loves the Blues, the trumpet player performs a brief solo. When it seems he’s finished the other musicians inhale dramatically, getting ready to play again, but the trumpet just launches into another elaborate riff. Then another. And another. Our resident heckler that night missed the spirit of the piece entirely, shouting for the soloist to cut it out.

Last year we gained brief national notoriety when two Boston Pops patrons got into a fistfight because one wouldn’t shut up during the show. What will it take before we recognize that once the curtain rises on a performance – any performance – the performers literally have the stage for as long as they want it?

As Aaron Sorkin put it in The American President, “You want free speech? Let’s see you acknowledge a man whose words make your blood boil, who’s standing center stage and advocating at the top of his voice that which you would spend a lifetime opposing at the top of yours.”