Sugarland, the reigning ACM Vocal Duo of the Year, are still trying to absorb all of the fun from their weekend in Las Vegas. For lead singer Jennifer Nettles, the highlight of her time in Sin City was being able to perform with R&B star Rihanna, as part of the awards ceremony.

"Obviously it was very exciting," Jennifer says about the collaboration (quote via CMIL). "The energy for me on stage was great. I think it felt comparable in the room. I don't know how it translated on television through the screen, but it felt great. I had a great time. I thought it sounded good." [Watch video of the performance below.]

The multi-platinum-selling duo caused quite a stir last year when they released their latest album, 'Incredible Machine,' which they described as "steampunk," and which was considered by many to be a sharp deviation from the country music format. But Jennifer says being able to perform with artists from other genres proves that their music is appealing to everyone, regardless of label.

"Country music is hip, cool, young and fresh, and I think [Rihanna] being there is even more a testimony to that," she notes of the ACM performance.

The duo have taken home the ACM Award for four years in a row, but they insist it never gets old. "These awards are really exciting because they are about the acceptance from your peers, or at least being celebrated by your peers," Jennifer says. "The duo category is a wonderful one to be in. I think everyone does a wonderful job. To do this job, there are accolades that need to be given to everyone, so to be singled out in a certain way by your peers is very special."

Known for her unique fashion sense on stage, the blond beauty wore long locks for Sunday's event, instead of her trademark short hair. The Georgia native says playing in front of millions of fans is the perfect time to debut a brand-new 'do.

"It's all about fun when we get to come to these the award shows. When you want something different, you just do something different," she says. "There is no deeper hidden message other than wanting to look glamorous and feel good about yourself and be able to have fun ... There is no secret meaning in my hair!"

Jennifer's singing partner, Kristian Bush, couldn't resist using her new look to poke a little fun at his other half. "You know what I loved about it?" he says. "I couldn't tell who was going to have extensions and who wasn't, Rihanna or Jennifer. Their hair both went to like three different lengths in a day."

Sugarland are in the middle of their Incredible Machine tour, along with opening acts Little Big Town, Casey James, Sara Bareilles and Matt Nathanson. Keep track of their schedule here.