Bright and early tomorrow morning, the Big Gig will drop its list of grounds stage headliners. But apparently Summerfest was just too excited to keep all of its announcements until then, so as a bonus, the summer festival today unveiled its latest American Family Insurance Amphitheater headlining act late: pop star Billish Eilish, who will take the stage on Saturday, July 6.

The hypnotic-voiced 17-year-old singer has blown up since she released her viral first hit, "Ocean Eyes," grabbing the industry's attention. Since then, Eilish has released her first studio album, last month's "When We All Fall Sleep, Where Do We Go?", which reached the top of the Billboard charts – the youngest artist to do so since 2015 – and scored multiple idiosyncratic pop hits, including "Bury A Friend," "You Should See Me In A Crown" and the Khalid collaboration "Lovely" from the second season of Netflix's "13 Reasons Why."

Tickets for this show will go on sale starting on Saturday, April 13 at noon at Ticketmaster and Summerfest's website. Tickets can also be bought in person at the Summerfest box office, Ticketmaster ticket centers and select Walmart stores.

The pop star marks the final Summerfest main stage headlining act announced for 2019 – depending on how the festival plans to handle the newly vacated Ozzy Osbourne slot on July 4 – so here's the Big Gig lineup as it stands:

June 26: Thomas Rhett
June 27: The Outlaw Music Festival
June 28: Jason Aldean
June 29: Bon Iver
June 30: Zac Brown Band
July 2: Lionel Richie
July 3: Jennifer Lopez
July 4: TBA (former Ozzy Osbourne date)
July 5: The Killers/Death Cab for Cutie
July 6: Billie Eilish
July 7: Lil Wayne/Snoop Dogg/ScHoolboy Q

And, obviously, there's much, much more to come tomorrow morning at 6 a.m., so stay tuned to OnMilwaukee.