Carrie Underwood went on national TV to announce her new single and album. The songstress appeared on the 'Today' show to share that she will release the song, 'Something in the Water,' from her upcoming 'Greatest Hits: Decade #1' album.

"It's really kind of a joyous, uplifting song about changing your life for the better and kind of having that 'a-ha' moment, to waking up and your life being different from that moment forward," she explains.

It was a fitting time to announce the upcoming song. The 'American Idol' winner is in New York City to perform for the Global Citizen Festival in Central Park, along with Jay-Z, The Roots, Sting and No Doubt. The event, which is part of the Global Poverty Project, works to eradicate extreme poverty by 2030, while also promoting volunteerism.

“They are so many causes," Underwood maintains. "You can find something that you’re really passionate about."

Underwood's performance at the Global Citizen Festival is one of her first since announcing her pregnancy earlier this month. The songstress, who is due in the spring, admits she still has a hard time wrapping her mind around the good news.

“It’s still kind of weird, to be honest,” she concedes “Sometimes I’ll be with my husband [Mike Fisher] and I’m like, ‘I’m going to be a mom. You’re going to be a dad. Like, is this real life?’ But we’re really excited.”

Thankfully, the 31-year-old had a good role model, who she hopes to emulate.

“I have a wonderful mother," she notes, "so if I can be even a little bit like that, I think we’ll be good."

In addition to her upcoming greatest gits package, Underwood is also working on another studio album, which will follow her platinum-selling 2012 'Blown Away' record.

“I’ve been writing a lot. It feels really good,” she says.“It’s just a progression, a different sound without losing myself in it. I’m not taking some crazy musical departure from what I’ve done, but it definitely feels different. It will feel different, look different, sound different.”

Underwood is taking the fall off of the road. After this weekend, she can next be found at the 2014 CMA Awards, where she will return as co-host, along with Brad Paisley, for the seventh year. She is also nominated for Female Vocalist of the Year, along with Musical Event and Music Video of the Year, for her duet, 'Somethin' Bad' with Miranda Lambert.

'Something in the Water' will be available on Monday, Sept. 29. 'Greatest Hits: Decade #1' will be released on Dec. 9.