Firefly Day One Highlights: Maggie Rogers' Festival Debut, Kaleo's Rootsy Rock & More

Musical guest Maggie Rogers performs 'Late Night with Seth Meyers' on May 8, 2017.
Lloyd Bishop/NBC/NBCU Photo Bank via Getty Images

Musical guest Maggie Rogers performs Late Night with Seth Meyers on May 8, 2017. 

Delaware's state capital of Dover will be filled with music fans throughout the weekend for the annual Firefly Music Festival. Thursday (June 15) marked the first day of the festival -- though a handful of acts performed Wednesday evening.

Day one served as an introduction to the headliner-heavy days to follow -- Bob Dylan, Chance the Rapper, The Weeknd, Twenty One Pilots and more -- as music started in the late afternoon (around 5:00 p.m. rather than noon) and ended at midnight, while Friday and Saturday will go until 2 a.m. 

Rising artists like Maggie Rogers and Kaleo delivered strong sets, veteran act O.A.R. ran through a setlist of hits and Glass Animals closed out Thursday evening with a late-night disco theme. Read more about Day one highlights below.

Maggie Rogers Makes Her Festival Debut 

"This is the first festival I've ever played," Maggie Rogers told the crowd. With her eyes painted in electric blue eyeshadow, Rogers sang songs off her debut EP Now That The Light Is Fading, such "Dog Days" and "On and Off." Halfway through the set she gushed, "I just don't think I'm going to get over this" before throwing on a pair of red-tinted shades. She then invited her friend and former New York University classmate, Fletcher, on stage with her to energize the audience with a cover of The Spice Girls' "Wannabe." She ended with the fan-favorite (and career-launching) "Alaska," which came out a year ago to the day. 

K. Flay Rocks an "Immigrants Welcome" Shirt

As the sun just started to set over the woodsy Firefly grounds, K. Flay's set served as the ideal transition into night. Dressed in all black, and sporting a shirt that read "Immigrants Welcome," the alt-hip-hop artist sang crowd-pleaser "FML" and "Blood In The Cut," off her recent major label debut, Every Where Is Some Where.  

O.A.R. Runs Through The Hits 

"The first show I played was in eight grade," says O.A.R. frontman Marc Roberge. "That's when I knew I wanted to do this forever." Having already been around for two decades, it seems he's accomplishing just that. Roberge unknowingly waves as he sings, clearly comfortable with the band's veteran status -- especially when compared to the rest of the lineup for day one. The rock group ran through "Heaven" and "Peace" before getting into an epic jam of "That Was A Crazy Game Of Poker" that they fused with a horn-heavy rendition of Bob Marley's "No Woman, No Cry." 

Kaleo's Frontman Whistles In Tune 

Icelandic bluesy-rockers Kaleo have had a successful U.S. crossover, evidenced by the large crowd they attracted. Frontman JJ Julius Son opened the set with a lengthy guitar intro that he then whistled over in perfect tune. The band's sound filled the open space well, while Son's raspy vocals sustained songs like "I Can't Go On Without You," "No Good," and -- as Son said -- "the only one we do in our native tongue,"Vor í Vaglaskógi." The group then ended its evening set with breakout hit, "Way Down We Go."

Glass Animals' Giant Pineapple-Shaped Disco Ball 

After opening with "Life Itself," Glass Animals' frontman Dave Bayley tells the crowd, "I always love playing the first day of a festival, because you guys take all your drugs." Serving as day one headliners, the English rock act performed while a large, bejeweled pineapple hung overhead -- doubling as a disco ball, and setting the mood for the late-night soft-rock to follow.