Atlas Genius - 5:15 to 6:15 p.m. -- WHERE Lawn Stage / Fetty Wap - 7:15 to 8:15 p.m. -- WHERE Backyard Stage

Atlas Genius

All it takes is hearing the synth-heavy “Molecule” to realize Atlas Genius has got the goods. A true band of brothers, Atlas features siblings Keith (vocals and guitar) and Michael Jeffery (drums) formulating an alternative-indie sound that has made their native Australia proud. The international band’s second album, “Inanimate Objects,” is an underrated treat. Songs on the project are consistently strong. Along with “Molecule,” the album offers the sugary “Refugees” and muscular “Stockholm.”

Fetty Wap

Rappers have always been in limited supply at Firefly and this year is no different. However, this year has the hottest rapper of 2015, Fetty Wap. Not much of a lyrical rapper, Fetty Wap’s appeal is sizzling beats and hypnotic choruses. Born Willie Maxwell II, the New Jersey native’s claim to fame is the 2014 “Trap Queen,” which exploded on YouTube, generating 450 million hits and counting. The song was such a smash that he performed it in concert with country star Taylor Swift. But Fetty didn’t stop there. More hits like “679,” “My Way” and “RGF Island” have helped to keep him popular.