Justin Bieber's two-night NBC special All Around the World premieres Wednesday night at 8 p.m. ET and now, NBC has offered a sneak peek at what we can expect.

The special documents Justin's whirlwind promotional tour for Believe, during which he performed a series of free concerts in various cities around the globe.  The sneak peek clip shows Justin's headline-grabbing show in Mexico City, which attracted 300,000 thousand screaming fans.  That's double the number who showed up for rock legendPaul McCartney's gig not long before in the same city.

"I've never seen anything like this," says Justin's manager Scooter Braun in the clip.  "There are people on the rooftops, there are people...everywhere.  Everywhere you look, there are people, and they're going crazy."

All Around the World will feature footage from each of Justin's promotional stops, including Monday night's concert at New York City's historic Apollo Theater.