And the Philly Music Fest mystery headliner is....

The mystery headliner at this year’s Philly Music Fest in October is … Waxahatchee.

That’s the moniker used by acclaimed songwriter Katie Crutchfield, who will be atop the bill on the second night of the PMF on Oct. 22 at Ardmore Music Hall, with @ as the opener. (Yes, the band’s difficult-to-Google name is @.)

That information could not be revealed earlier when the PMF was initially announced in May because Waxahatchee — whose new album Tiger’s Blood marks a new high mark for Crutchfield’s writing and is one of the best records of the year — had two shows to play in Philadelphia that the Ardmore gig would have been in competition with.

In music industry parlance, it’s what’s known as a “radius clause.” When a band is booked at one venue, other venues within a certain geographical area agree to not also book the act, so ticket sales are not adversely affected. In this case, the venue that Waxahatchee was already scheduled to play was the Fillmore, the Fishtown concert hall.

Waxahatchee headlined the Fillmore on Saturday and Sunday night, , fronting an impressive band that included Wilco leader Jeff Tweedy’s son Spencer on drums.

“This is the last night of a very long tour,” Crutchfield said at the Fillmore on Sunday. “And I can’t think of a better place to have the last night of tour. You guys are coming in hot, and I like it.”

And now that those dates are passed, the Philadelphia Music Fest is free to put out the word that Crutchfield — who previously played the fest as a solo act in 2018 and who lived in Philadelphia through most of the 2010s — will perform with her full band in Ardmore on Oct. 22.

“We are beyond excited to welcome Waxahatchee back to Philly Music Fest,” festival founder and producer Greg Seltzer said in a statement. “Katie wrote so many amazing songs while living in Philly and despite the move to Kansas City, we’ll always consider Katie a Philadelphian.”

To use another music industry word, the Ardmore show qualifies as an “underplay.” As her audience has grown, Waxahatchee is now big enough to play two nights at the 2,500-capacity Fillmore. For the PMF, she’ll be doing one show at the far smaller Music Hall, which holds 500.

The Philadelphia Music Fest kicks off Oct. 21 and runs through Oct. 27 at six different venues. Other headliners include Slaughter Beach, Dog, in Ardmore on Oct. 21; Sheer Mag at Johnny Brenda’s on Oct. 23; Amos Lee at World Cafe Live on Oct. 24; Catbite at MilkBoy Philly on Oct. 25; Devon Gilfillian at Underground Arts on Oct. 26; and Glass Band at Solar Myth on Oct. 27.

Tickets for the Waxahatchee show and all other dates are on sale at phillymusicfest.com.