"You shouldn't have to think about that sort of thing happening, especially in this atmosphere where people are coming to enjoy music and really escape from that," Nashville-based soul singer Jonny P told CNN Friday, referring to the Las Vegas shootings and deadly attacks on other concert venues in recent years.
Some 75,000 people are expected to descend on downtown Austin, Texas, for the festival each day as the nation reels from Sunday night's sniper assault on the Route 91 Harvest Festival -- which left 58 dead
and nearly 500 others wounded.
The organizers behind Austin City Limits, which opened Friday, said they have worked year-round with local authorities to "plan and rehearse security and response plans."
"Safety has always been our top priority," ACL's promoters C3 Presents said in a statement this week.
The Las Vegas slaughter came about four months after a lone bomber outside an Ariana Grande concert at England's Manchester Arena killed more than 22 people, and three gunmen opened fire inside France's Bataclan concert hall in November 2015.
"We feel really heartbroken," said Cristal Ramirez, singer for the quartet The Aces. "Concerts are supposed to be a place of unity and a safe space."
More police officers -- uniformed and undercover -- will patrol the sprawling festival grounds this year along with Texas Department of Public Safety troopers, Austin Police Chief Brian Manley told CNN
"We can't come into this year's event ... after the massacre in Las Vegas and not have reevaluated our plans," Manley said.
"So we came in early this week and looked at the plans that we have in place ... We did make some changes."
Security plans include hardened barriers around the venue and the scrutiny of taller buildings near the grounds.
"When we look at this area -- being a major city park -- there are some areas of high ground," Manley said, alluding to the Las Vegas gunman's sniper nest in a suite on the 32nd floor of the Mandalay Bay hotel, hundreds of yards from the outdoor concert.
"We're aware of where they are and we've taken steps to address them."
A regional law enforcement intelligence center has been evaluating security and potential threats, according to Manley.
"But we live in a world now where you cannot protect large events, entire communities, from every threat," he said, urging concert goers to be vigilant and report any suspicious activity.
In addition, C3 Presents has been implementing tighter security measures over the years, including pat downs, bag searches and enhanced security inside and outside the festival, according to the promoters. A full list of prohibited items and details about security measures are posted on its official site.
The Zilker Park festival will feature acts such as Jay-Z, Red Hot Chili Peppers and Chance the Rapper. A total of 450,000 people attended the six-day event in 2016.
ACL is also offering refunds for people who no longer wish to attend because of the Las Vegas shooting, CNN affiliate KEYE-TV reported.
"I'm glad that they're doing that because, obviously, right now it's a really tough to be around big crowds," concert-goer Matt Schmitz said.
Sunday's massacre unfolded at the Route 91 Harvest Festival as country star Jason Aldean performed. It is considered the deadliest mass shooting in modern American history.
"Sadly, it makes you look at people differently and that's what we're hoping to kind of counteract, even with the songs that we did ... switching our sets up to really speak to people and kind of uplift everyone again and just realizing that we're not all bad," said the Bronx-born artist Jonny P.
"It feels really powerful to be here in this moment coming off such a tragic event -- to be able to speak and sing and be a light to people. We feel really fortunate for this opportunity."