Heard this song in AE, a girl is singing.

I was just catching the end of it, but it sounded like she was saying "dark stars" at the end or something like that. She kept repeating it occasionally, then the song goes into a heavy outro with distorted effects/guitars. Very alternative sounding at the end. Can anybody ID it?

Here are songs from the recent playlist with female singers which at least sound a bit like the one you describe
Duke Spirit - My Sunken Treasure
(Modest Mouse - Ocean Breathes Salty) - male voice, yes, but still sometimes high-pitched ... so I thought I keep this on the list
Metric - Gimme Sympathy
Hole - Celebrity Skin
Lady Sovereign - So Human

It's not any of those, but I did like the "Gimme Sympathy" song.

I think it's Many Moons by Janelle Monae maybe?

Nope, not that one. Somebody has to know. It's a girl singing, not a guy, so that should narrow the list down substantially. It sounds like the Yeah Yeah Yeahs, like I said it's very heavy on effects and guitars at the end. Oh well, I guess I will never find out. Maybe that store was using an old playlist.