The lineup for the 2020 Firefly Festival in Delaware has been announced, and the quality of the headliners has been upgraded this year.

Grammy clean-sweeper Billie Eilish, reunited rap-rock firebrands Rage Against the Machine, and pop star Halsey top the bill for the festival, to be held from June 18 to 21 at the Woodlands in Dover.

Having female artists in two of the three leading spots counts as progress in the gender-equity battle in the male-dominated festival world.

The second-string headliners, with their names in a slightly smaller font size in the lineup announcement, are pop-R&B songwriter Khalid, pop-punk vets Blink-182, and rising star Maggie Rogers, who lost to Eilish for a best new artist Grammy last Sunday.

For Firefly, the big gets are Eilish and Rage Against the Machine. The former became the first woman in Grammy history to sweep all four major categories on Sunday and only the second artist to do so, after yacht-rock “Sailing” singer Christopher Cross in 1981. Before she arrives at Firefly, Eilish will play the Wells Fargo Center in South Philadelphia on March 13.

The members of Rage — fronted by rapper Zach de la Rocha and guitarist Tom Morello — are back together this election year for more political agitation, playing three shows in the Southwest United States in March and the Coachella and Boston Calling fests before they get to Firefly.

The band’s most notorious festival appearance came in 1993 in Philadelphia when the Lollapalooza festival was held on the site of the demolished JFK Stadium. In a silent protest against music censorship, the foursome appeared onstage naked, with their mouths taped shut and the letters PMRC — for Tipper Gore’s Parents Music Resource Center — written on their chests.

Past Firefly headliners have included Paul McCartney, Tom Petty, and Kendrick Lamar. Last year’s top trio was less stellar, however: Panic! at the Disco, Travis Scott, and Post Malone.

Also notable at Firefly this year will be Kentucky rock band Cage the Elephant, former Philadelphia DJ-producer Diplo, hard-hitting rap duo Run the Jewels, Scottish synth-pop band Chvrches, rapper Lil Dicky, OutKast rapper Big Boi, Colombian-American singer Kali Uchis, and Van Halen song and dance man David Lee Roth. Philadelphia-connected acts include neo-soul man Devon Gilfillian and Lititiz, Pa.-born rockers the Districts.

For those who register online at the Firefly site, a ticket presale begins at 10 a.m. Friday. Tickets go on sale to the general public on at 10 a.m. Monday, Feb. 3. More information at fireflyfestival.com.

The 2020 Firefly Festival lineup.
Firefly Festival
The 2020 Firefly Festival lineup.