In what Brad Paisley had previously hinted would be the highlight of the show, Carrie Underwood sang the hymn "Softly and Tenderly" as a tribute to the victims of the Oct. 1 mass shooting at the Route 91 Harvest Festival in Las Vegas, Nev.

Underwood sang while standing on a round stage in the middle of the audience, and was encircled by people holding lit candles. (The rest of the arena audience could also be seen holding what looked like candles.) To mark the solemn occasion, she had changed into a long white dress with rose appliques and a long train, which was spread out so the dress puddled out beneath her.

"Softly and Tenderly," which has also been covered by Alan Jackson and Anne Murray, was the perfect choice for Underwood. She started off taking a restrained approach, and slowly added in intensity and emotion as the song progressed, until it crescendoed with soaring, confident arcs. Underwood never over-sang, however, which made the performance even more powerful.

This ending dovetailed with a tribute to the Route 91 Festival victims. In fact, there wasn't a dry eye in the house as photos and the names of each of the people who died flashed on the screen. Underwood herself sounded like she choked up and had to stop singing; at the end of the performance, she could be seen wiping tears from her eyes.

The performance doubled as an in memoriam to recently deceased country artists, as black-and-white photos of artists such as Tom Petty, Gregg Allman and Glen Campbell were also projected on a screen behind Underwood. In a nice nod, this section also included previous CMA Awards footage of Glen Campbell, Don Williams, Troy Gentry and CMA Exective Director, Jo Walker-Meador.

Prior to the 2017 CMA Awards, show co-host Paisley explained that he and co-host Underwood would help honor those who died and were injured during the Route 91 Harvest Festival shooting; however, Paisley noted that they were trying to strike a balance.

"We're not going to ignore it, but we're not going to also dwell on that," Paisley said. "We have to make sure we honor those we've lost, but we also [have to] celebrate this music, which lives on, and do a good job having the heart we need to have on that night. And also the theme of the show this year is very much about unity and coming together as a format."

Jason Aldean was onstage, closing out the final night of the three-day Route 91 Harvest Festival, when a gunman opened fire on the festival grounds from a hotel room at the nearby Mandalay Bay. More than 50 people were killed and more than 500 people were injured.

On top of her hosting and performing duties, Underwood also received a nomination at the 2017 CMA Awards: She was up for the trophy in the Female Vocalist of the Year category, but lost to Miranda Lambert. Her new concert film, The Storyteller Tour: Stories in the Round -- Live From Madison Square Garden, will be available on Nov. 13.

Top 10 CMA Awards Moments

Unforgettable CMA Awards Controversies