Pounding music Pyrotechnics Leprechauns on stilts Dancing girls And Kevin Garnett screaming from the scoreboard

BOSTON — Where to start?

Is it with the pounding music, as if a band is playing inside your head?

Is it with the dancing girls with their sequined uniforms?

Is it with the Jumbotron that hovers over the court like some omnipresent seeing eye?

Is it with the leprechaun on stilts?

Is it with the pyrotechnics?

Is it with the ringing of a bell as the dramatic music rises?

Is it with the Jumbotron that screams out, ARE YOU READY?

Is it with a giant close up of Kevin Garnett’s face on the Jumbotron and he is screaming?

Is it with the constant, unrelenting, nonstop activity, compete with a soundtrack that seems to shake the arena?

It was all there Sunday night, all there in the new Garden as the Celtics opened up the playoffs against the Atlanta Hawks.

And this is all before the game started.

Rest assured these are not your father’s Celtics anymore.

Oh, yeah, there are homages to the past, a montage of images that flash by on the Jumbotron, cheers for Red Auerbach, more cheers for images of Larry Bird.

But that is all just a quick prelim, as irrelevant as a layup drill.

This is about pro basketball in this new millennium and any resemblance to the Celtics’ glory days of 20 years ago is almost accidental, as gone as the old Garden.

Back then going to a Celtics’ game was like going to a basketball cathedral, as pure as some kid shooting baskets by himself in some lonely park in the dying twilight.

No frills.

No bells and whistles.

No dancing girls.

No show.

Just basketball.

That had been the appeal of the old Garden — the players changed, but the atmosphere never did. No music. No cheerleaders. Nothing to tell you that it wasn’t 1957 anymore.

The only entertainment?

John Kiley playing the organ.

Let the Lakers have the Laker Girls, the Hollywood flash. This was basketball the way it always had been, basketball the way it was supposed to be.

But by the time the Celtics moved into the new building in the mid-’90s all that was gone, baby, gone.

Things were changing, a younger crowd, more raucous, more of a party atmosphere, complete with rock music and video images of people dancing in the stands during timeouts — a basketball game as an event.

It was a brave new world of entertainment, the underlying philosophy being that just a basketball game was no longer enough anymore. It was all geared to be “fan friendly,” what one Boston sports writer had once called “Hooterville,” after a trip to Orlando.

Now it’s all “Hooterville,” as if all the league’s marketing people attended the same seminar.

Now it’s welcome to the basketball circus. See a game, win a T-shirt.

And it’s not the only difference.

My seat Sunday night was in a makeshift press table about 20 rows up in the stands. In the two rows in front of me were roughly 30 people, 25 of whom were all wearing some form of green Celtics’ gear, whether it was jerseys, T-shirts, or shirts with PIERCE or GARNETT in the back of them.

That’s the other thing that’s so different now than it used to be, the presence of so many people wearing green. They are everywhere.

They also are on the Jumbotron during virtually every timeout, a zillion people wearing green. Adults. Little kids. And everything in the middle. They danced for the camera. They preened for the camera. They shook their fists to it. Over and over it went, as the music reverberated around the arena, everyone pumped up and ready for a party, an NBA version of spring break.

One guy had a basketball on his head. Another, who looked old enough to have seen the Cooz in his prime, had a curly green wig on his head. Many had their faces painted. A little kid, no more than five, danced in the aisle. And the music kept blasting, unrelenting.

Where have you gone, John Kiley?

There was a group of young kids in white Celtics jerseys called Lil Phunk who did a dance routine, as four acrobats were on the periphery.

The Red Sox trio of David Ortiz, Dustin Pedroia and Mike Lowell, who were sitting in the front row, appeared on the message board and got a huge cheer, as Springsteen’s “Glory Days” bounced around the arena.

Larry the Leprechaun ran up and down the sideline as “Rock the Garden” flashed on the Jumbotron. Later, during another timeout, he jumped off a trampoline and threw down a thunderous dunk, taking the ball out of Ortiz’s hand as he flew by.

The Celtics’ dancers ran out on the court and threw T-shirts into the crowd.

Could you make this up?

Not really.

Not if you remember when the old Garden was a basketball cathedral, back when it was assumed that the game was enough to get people excited, that they didn’t need the promise of a T-shirt, and a game that comes with its own soundtrack.

For this is about more than basketball. It’s about entertainment, and it’s about non-stop energy. Frenetic energy, an orgy of excess. It’s about spectacle, like some rock concert with a lot of special effects, Kiss in sneakers.

And if you didn’t know any better you might think that it’s really about the circus with a basketball game squeezed into the middle of it.

breynold@projo.com