To say there’s a difference between a legacy or digital publisher’s NewFront and a tech company’s NewFront would be an understatement.

True, both events generally feature free booze, an assortment of small bites, blaring music, sleek videos, some sort of celebrity — maybe even a musical performance — advertising types using jargon like “CPM” and “scalability” and marketing spin— but that’s where it ends.

At YouTube’s event, which it dubs “Brandcast,” there was a full slate of activities. Held Thursday night, the Google-owned company rented out the entire north hall of The Jacob K. Javits Convention Center in New York. Half of the hall was converted into a theater where roughly 2,800 guests would hear execs and celebs talk about the company’s offering this year, and the other half of the hall was turned into a carnival-themed dining area where food would be served after the presentation. After dinner, guests were invited back into the auditorium for a concert by Katy Perry.

Perry wasn’t the only celeb to make a cameo at the event; James Corden and Kevin Hart stopped by, too. There were also musical numbers, dancers and confetti. But before the event hit those high points, YouTube had a little explaining to do.

The last few weeks have been rough, as a slew of clients pulled their support after their ads appeared next to inappropriate content.

“Never before has so much creativity be unleashed, but we realize with that with that creativity and openness comes responsibility,” said chief executive officer Susan Wojcicki. “The last several weeks have been challenging for some of you, and you’ve told us to do better when it comes to ad placement. I want you to know that we have taken your feedback to heart. We work hard every day to earn our advertisers’ and agencies’ trust, and we apologize for letting some of you down. I’m here to say that we can and we will do better.”

The ceo said their teams are “working around the clock” to make changes to “ensure that” their partners’ ads “show up in the right place.”

YouTube said it is offering more controls for brands and that it is working with third parties like ComScore and IAS.

Wojcicki thanked advertisers and later, she would drive home the power of the platform as a voice for diversity and a disruptor in media.

“YouTube is not TV. And we never will be,” she said. “The platform that you [advertisers] all helped create represents something bigger,” she said. “Our users don’t come to YouTube for polish, they come to YouTube for texture. They come to see the world as it truly is, filled with people just like themselves. They come to witness our shared humanity.”

Once YouTube’s mea culpa moment was behind it, the company brought on James Corden, who lightened the mood by performing a Broadway-inspired number about YouTube.

“Nothing quite says YouTube like a big YouTube camp musical number,” Corden said before busting out into song.

“When the world leaves you weary. When life feels routine, you always know the place to go, just inside your screen. YouTube!,” he crooned, while dancers came on to the stage; later a person dressed as Pokémon’s Pikachu would join in the fun.

But on to business. YouTube announced a slate of ad-backed original series, which included “Best. Cover. Ever.,” a series from Ryan Seacrest; “Ellen’s Show Me More Show,” a series from Ellen DeGeneres; “I Am: Demi Lovato,” from you guessed it — Demi Lovato; “Good Mythical Morning,” from YouTube stars Rhett and Link; “The Super Slow Show,” from The Slow Mo Guys; “The Katy Perry Live Special,” and Kevin Hart’s “What the Fit.”

Both Perry and Hart were on hand to plug their shows. Hart’s show mixed the comedian doing new workouts and making people laugh. Hart is also launching a network called “Laughing Out Loud.”

Hart described the network as a “multicultural streaming service for comedy.”

“Now I can give back, and create an opportunity for others, for writers, future comedians, actors and give them a platform to distribute,” he said.

Perry, who sported a platinum crew cut, would later join Corden, who became a sort of MC of the event. The audience seemed confused at first by her appearance until she busted out a few lyrics.

Perry said she would work on Seacrest’s show, as well as host a live-stream “listen along” for the break of her upcoming album.

“I’m really excited to be in The YouTube family. I feel like I was born on the Internet,” she said. “I started on Myspace. Remember Friendster, anyone?…I remember uploading videos myself to YouTube….life comes full circle, doesn’t it?”

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