I have been going to the theater for (sob) 60-some years, and seen wonders. Brando in “A Streetcar Named Desire” — I was there. Ethel Merman in the gypsy run-through of, yes, “Gypsy” — caught that, too. Olivier, George Scott, Page and Hepburn (Audrey), Pacino, then unknown. Saw them all.

I treasure the memories, always will, because, when it works, the theater is better than anything.

And it sure was working at the St. James Theater last Thursday night when, at 8:06 this wild burst of applause broke across the audience. Know what cued it? If you’ve seen “The Producers” you’re probably guessing Nathan Lane’s rendition of ‘The King of Broadway,’ which does, in fact, stop the show right at the top. But you would be wrong.

The applause was caused by this: The house lights dimmed.

We are talking, folks, about a hit.

How big, as Mr. Carson once used to ask, is it? Well, as big as “A Chorus Line” or “Fiddler on the Roof” or “My Fair Lady” — pick one. Amazing.

But for me, the importance of the Mel Brooks musical is its success. It is the final nail in the coffin of the shit that has been flooding the theater for 20 years. It is, if you will, finally and blessedly, the death of Andrew Lloyd Webber.

Lloyd Webber, let it be noted, is still a very young man. And he will make more money next Tuesday than most people earn in a lifetime. His shows still run all over the world, and he has new ones aplenty.

But he doesn’t matter anymore. And a good thank God for that. I remember years ago fleeing the Majestic Theater where “Phantom of the Opera” had just opened, and I swore to myself — I still remember the moment — that I would never see another piece of mock opera.

The Lloyd Webber oeuvre — and he is not alone — is full of special effects and phony emotions, and boy do you know he listened to a lot of Puccini when he was a kid.

I didn’t just hate it, I found it dangerous.

Why? Because no bright young American writer would want to work on Broadway. If you’re one of those neurotic brilliant people — one of those who gets chills when someone sings “flying too high with some guy in the sky is my idea of nothing to do” — well, the theater was no longer a place you wanted to be associated with.

Broadway had become Lloyd Webber bloat.

But it’s all changing now. Which is what that burst of applause was when the house lights dimmed. Welcome, the audience was saying, great to see you again.

Because what Mel Brooks, has done is bring flat-out entertainment back to the musical theater. There will be no doctoral dissertations written about symbolism in “The Producers.” There are no chandeliers crashing here — try good jokes, gags, nutty rhymes, weird, crazed characters, serious and funny at the same time.

And all you out there who knew Cole Porter wrote that quintuple rhyme, pay attention now — give up those sitcoms you’re all getting rich writing. And bank your money wisely.

And come back to the theater. All is forgiven.