I'm happy to. It's all about one of my favorite things. Cma music fest. When musicians get a chance to meet fans and perform in settings big and shall. This year, the wonderf little big town are... See More
I'm happy to. It's all about one of my favorite things. Cma music fest. When musicians get a chance to meet fans and perform in settings big and shall. This year, the wonderf little big town are hosting tonight's abc special on the cma fest. More on that in a minute. First, behind the scenes of the festival with rachel smith. ♪ Long as I live ♪ Reporter: It's country music's most important week of the year. The cma musing fest. What gets you coming out year after year for the fans? It's all about the fans. Without the fans, it's just one big long sound check, isn't it? Reporter: And in a sign of the times, ronnie dunn faced a flash mob. The rules are there are no rules anymore. It's our chance to say thank you. We jumped at every opportunity to hang out and sign. Reporter: Artists like "dancing with the stars" champ kellie pickler, this week is a homecoming. So honored that the country music hall of fame asked me if i would donate my outfits and the mirror ball trophy. I was like, absolutely. Are you kidding me? It's the best feeling in the world. People that we have loved for so long, admire them, just getting to meet them. I was like -- I think this is our fourth year. Every year, they have given us more and more time on the stage. Reporter: This year, a surprise genre-bending jam session. I love collaborating with people. I had a great time. He has great mu zigss and song writers. Reporter: Meanwhile, jake owen is juggling daddy duty. I changed a couple of diapers today. I don't mind the number one. Reporter: But the number two is a different story? I go here you , mama. Reporter: Duck dynasty doped by. We have our christmas album coming out. Reporter: So I hear. Our fans are known as being so loyal. Reporter: And the dynamic duo of carrie underwood and brad paisley have co-hosted five times. There's still nerves there. If you're not nervous, you don't care. Reporter: For "good morning america," rachel smith, abc news, nashville. You can see so many trif irk performances on a very big special, "cma muzic festival, country's night to rock" tonight at 8:00, 7:00 central on abc.
This transcript has been automatically generated and may not be 100% accurate.