YouTube Brought Back Some Of Its Biggest Stars To Celebrate Its 9th Birthday

On April 23, 2005, the very first video was uploaded to YouTube.

But the video wasn't made public until May 29 of that same year, which is the date the site considers its birthday.

Since then, YouTube has exploded, with more than 100 hours of video being uploaded every minute.

So it's celebrating its 9th birthday in style: by commemorating the music everyone has made on the video site.

In a statement, YouTube writes:

To call out just a few highlights in YouTube history, there are more than 120,000 videos inspired by "Let it Go" (based on videos posted with that title), half a million by "Gangnam Style," and a stunning 1.5 million videos by "Harlem Shake" (that's a lot of motorcycle helmets). These inspired riffs got us thinking about those magical moments when songs become bona fide trends-and people all over the world start remixing, covering, parodying, dancing, and lip-dubbing.

So to celebrate this year, we pay homage to the music you've made on YouTube. We got a bunch of your favorite performers together to cover some of the most memorable musical moments in YouTube's history. The result is a mashup called YouTube Birthday Karaoke Night, featuring familiar faces like The Gregory Brothers, Chester See, Cimorelli and more (see if you can spot all 18).

YouTube was founded by three former PayPal employees - Chad Hurley, Steve Chen, and Jawed Karim - in February 2005. It began as a personal video-sharing service, rather than a video search engine, which is what made it stand out.

The video starts with one of the most well-known of all the silly YouTube songs, "Chocolate Rain":

And then the singer of "Chocolate Rain," Tay Zonday, pops in to give us a taste of another silly YouTube special, "The Bed Intruder Song."

Mystery Guitar Man, whose channel has more than 2.8 million subscribers, makes a cameo to sing "Trololololo."

And it just keeps getting better from there. You might not recognize all the faces, but you'll definitely recognize the songs.

Check out YouTube's celebratory compilation video below: