The singing group, made up of members of the Colorado's Air Force Academy, known as In The Stairwell has made it through to the LIVE finals on America's Got Talent. 

The 15 member all-A Capela group grabbed one of the very few coveted finalist spots with their take on N*Synch's "Bye, Bye, Bye".

It wasn't an easy road for them. At the very first audition, Howie was not impressed. In fact, Howie buzzed them. Thankfully, Mel B., Heidi and Simon all liked them and gave them three yeses.  On the second performance, they were able to change Howie's mind.

The live finals begin tomorrow (Tuesday, August 15) from Las Vegas.

They definitely are a crowd favorite. A large part of that is that they are serving this country, but also because they're pretty good. I didn't necessarily like the N*Synch song, but they got through. For their next performance, they are going to have to bring it, big time. That means song choice is crucial. Do not do "Hallelujah." Do not do "Somebody That I Used To Know." Do not do any boy band songs, either. Dig deep, guys. This has to be an unbelievable performance. Good luck and thank you for your service.

This was their first audition on the show: