Thompson Square has been hard at work on their sophomore album, and now they're giving fans a taste of the project's first single. "If I Didn't Have You" comes out Oct. 30, with songwriting credits going to the duo's Keifer and Shawna Thompson, along with Jason Sellers and Paul Jenkins, who also share credit for the couple's Top 10 hit, "I Got You."

"The song is a story about two people who rely on each other to get through the tough thing we call life," the husband and wife write on their website. "We all have someone who we can go to for encouragement, and this is our story. We hope you love it as much as we do."

As for how the entire album is shaping up, the "Glass" singers write, "We're working very hard to bring you songs that are the very best that we can produce and very excited and proud of how it is shaping up." (Listen to a 90-second preview of "If I Didn't Have You" here.)

Before the love birds -- who have been married for 13 years -- share their musical biography, they'll celebrate the anniversary of their engagement. Keifer admits, though, that when he popped the question on that October night years ago, he wasn't able to give his wife-to-be the ring she deserved.

"I didn't have any money at all when I asked Shawna to marry me," Keifer recalls to Chicago's US 99.5 radio station. "I went out and picked out the ring I wanted to give her but I couldn't afford a diamond, so I had them cut a piece of glass the same shape the diamond was."

He found the perfect moment to surprise her after picking out their Halloween pumpkin. "Shawna cleaned out the pumpkin, because I don't touch the gooey stuff," Keifer explains. "I had put the ring at the bottom of the pumpkin and [when] she came back to put the candle in she pulled it out bawling."

While times were tough when he asked for her hand, Keifer made sure to get Shawna the real deal before they walked down the aisle. "The week we got married I replaced [the glass] and said, 'Let me get your ring cleaned, it's so dirty!'" he remembers. "I switched it to the actual diamond and she said, 'Wow, it's really clean now.' It's a bit cheesy, but it worked."