Zedd: "The people from Letterman were interested in me performing for quite some time. We've been discussing that whole thing for a few months. The problem was I didn't want to just go up there and press play and dance to the song. I wanted it to be special, I wanted it to be something that no one else can do. It's not easy to figure out something that is unique, that you can pull of live and still connect to your fans deeply.

"Basically, the version of 'Clarity', it's an electronic song, in the complete opposite way, just acoustic, 100% real instruments, no electronics to show people that my music is not just beats, and vibes, and waveforms; it's actually music that you can play out if you wanted to.

"That was kinda my vision so I changed the course of the whole thing, which we started shooting with the acoustic video I uploaded a little before that, then we arranged the whole thing for an orchestra and one day before the performance I actually recorded a full orchestra 28 piece version in L.A, got all the sheet music, then flew to New York to the Letterman performance. We literally had two or three times to rehearse it before we had to perform it. It was a very last minute thing although we plotted for so long. We got the confirmation five days before the show. It was the craziest five nights without sleep I've ever had in my life.

"I called Alvin [Risk, an EDM producer who sang back-up during the live performance] around 1AM and said it's going to happen and that I'd was on Letterman the next morning. He didn't say he would come or anything and then the next morning i woke up and he was in the lobby. He took a flight at 6am from Miami to New York and then he was just here.

He was like, 'Hey, I just wanted to be here.' He asked when the performance was. I told him but by that time he would have to fly back already because he had a show that night. So he flew all the way there without knowing when I would perform and he would actually miss it.

"So we made some calls and I told the promoter of that show he was playing that he has to be with me on TV and we decided to give him the role of a backing vocalist. It was very last minute, but if there's a way to kind of support the dog, we'll always do that, that's how we roll."