It was an impromptu moment, and it was a beauty.

It was a moment that occurred during the Todd Bowles era about, um, never.

And it was a moment symbolic of the electric energy and personality the Jets’ new coaching regime is bringing to the field — particularly evident in these early days of training camp because everybody is finally on display.

So there was Gregg Williams, the Jets’ defensive coordinator who proudly carries his reputation for unapologetically kicking ass first and taking names later, marching up to the large grandstand of fans sweltering in the morning sun and standing before them as if he were at a pulpit.

“I can’t tell you how happy I am to be here, and all eight of the defensive coaches that get a chance to listen to me,’’ Williams told the crowd. “They’ve all been on multiple staffs with me before. Four of them played for me and I helped them get into coaching. I don’t have to convince any one of those eight defensive coaches how ‘effed-up’ I am.’’

Then Williams talked about his players, saying, “These players right here have not pushed back a bit. They want to be coached. They want to defend MetLife Stadium for you guys.’’

With that, Williams got a rousing ovation, and he turned around and continued coaching.

Head coach Adam Gase, speaking after practice, said he never even saw Williams speak to the crowd, but he said, “That’s him. He’s like that all the time. Every morning he’s ready to go, he’s ready to compete, ready to meet with the players. He thrives on interaction with the players. He loves getting those guys understanding and believing in what they do.’’

It’s a fascinating dynamic, this Gase-Williams marriage. Gase is a Type-A personality, and his defensive coordinator is Type-A-plus-plus-plus — if there’s such a thing.

It’s a potentially combustible combo platter that could go “boom’’ should things go sideways for the Jets.

But it, too, has potential to be a powerful marriage, because Gase’s philosophy on offense is to attack and Williams probably would like his defensive players to take out a few security guards on their way off the team bus on game days — just as an appetizer.

Gase called Williams’ way of coaching “fun to watch,’’ adding, “I’ve learned a lot just watching how he develops their philosophy and their culture on the defensive side of the ball. There’s a lot of really good stuff that we’ve been able to use and apply on our side of the ball as well.’’

The players are jacked up about playing for Gase and Williams. The returning players are well aware they were a dead team walking under the watch of Bowles, who never evinced himself as a leader of men.

“There’s a difference in having energy for no reason and having energy with confidence and swagger to back it up,’’ linebacker Brandon Copeland told The Post on Sunday. “I’m excited for this season because it seems like we have the latter now, a sense of confidence and backing it up, holding each other accountable. It’s nothing but positive, great energy. It trickles down. It’s contagious.’’

Avoiding the wrath of Williams is a key component to everyone’s happiness. Here’s the thing, though: Avoiding the wrath of Williams is virtually impossible.

“When you hear him yelling and getting after players, guys don’t take the tone personally,’’ said Copeland, who played under Williams during his rookie year at Tennessee. “Guys take the critique and they use it to get better. It’s not coming from a bad place; it’s coming from a place of love and experience. You understand that his tone is one of love. You can tell he’s passionate about the game.’’

Linebacker Jordan Jenkins called Williams “loud and angry’’ and added, “He’s my type of guy — balls to the wall. It’s to my liking.’’

Linebacker Avery Williamson said Williams “is always testing you.’’

“Every day, he’s like, ‘What do you want to be? Do you want to be great or what?’ ’’ Williamson said.

“There’s just a lot of positive energy, man,’’ Copeland said. “The biggest thing is making sure we back it up.’’

Williams is quite sure he’s going to back up his reputation as one of the great defensive minds in the game, but he’s not averse to a little bit of humor to lighten the mood.

At one point about midway through Sunday’s practice, Williams spotted a youngster wearing a Jets helmet in those same grandstands before which he’d grandstanded earlier and said, “I’m glad you’re wearing a helmet, because if I get pissed off at someone, you’re going in.’’