There is only One Direction in pop music and the band of the same name are on it, all the way to the top. Especially here in the States it seems, where One D mania is already off the charts.

When Niall Horan, 18, Zayn Malik, 19, Liam Payne, 18, Harry Styles, 18, and Louis Tomlinson, 20 signed up with X Factor svengali Simon Cowell they couldn't have known they would soon become the first British and Irish group to debut at number one with their first album, Up All Night.

For some perspective on that achievement remember that not even The Beatles or the Rolling Stones enjoyed that level of success at the starting gate. And for even more perspective, it’s fait to say One Direction have yet to write a pop song to rival The Beatles or the Rolling Stones in their heyday - the truth is these boys don't even write their own songs, yet.

But according to when the band were making their first public appearance in the US at Boston’s Natick Mall on March 4, they were greeted by over 5,000 screaming young fans. And then in the ultimate test of fame in the digital age, they've already racked up 87 million YouTube views. So things are really looking up for the biggest boy band since the last big one.

Next on their wild ride to the top will come a uniquely American rite of passage: their first Saturday Night Live gig. Tonight the lads will star alongside comedy bombshell Sofia Vergara.

The promo video released earlier this week shows the young super group riffing with Vergara and SNL regular Kenan Thompson. In the video, which was previewed by the Daily Mail, Vergara introduces herself and the band before adding, 'I’m so excited to be surrounded by all these cute young popstars.'

Not to be outdone Kenan, 33, asks to be counted in saying: 'Yeah, all of us, so cute and young. I’m like you guys right?’ Niall then enthusiastically chimes in: 'Yeah, you are man, yeah.'

Now that's comedy.

One Direction play ‘Saturday Night Live’� NBC