Don't Smile at Me | Billie Eilish

As if you couldn't deduce it from the irritated glare she shoots you from the cover of her debut extended play, Billie Eilish makes it pretty clear that she doesn't want you to smile at her. And she doesn't want to smile at you.

From a stranger's perspective today, it may be hard to believe that her earliest single, "Ocean Eyes," is a feathery, non-confrontational synthpop track that was recorded in her brother's bedroom for her lyrical dance group. Her fluid vocals run like a stream over lightweight production, and when the track found its way onto every trending playlist on the web, Eilish was deemed the world's next best do-it-yourself hit-maker. And although Don't Smile at Me makes a finale out of "Ocean Eyes," its remaining tracks are products of an unrecognizable Billie Eilish.

Despite a much more professional guise, Don't Smile at Me is an in-house product in its entirety. Her brother, songwriter and former Glee actor Finneas O'Connell, co-wrote the extended play and produced it himself, throwing his sister's pastel voice over a distinct mixture of acoustics and electronics. At her most intimidating, she can unhinge over low-riding bass that can shake the dead from their slumber ("Copycat," "Bellyache") or grab a ukulele and leave a twinkling musical voicemail to confront a boyfriend ("Party Favor"). In that last one, she's cool and collected as she twists the knife in her send-off: "And I hate to do this to you on your birthday... Happy birthday, by the way."

Eilish is edgy in the most marketable way – and she is perhaps the most believably edgy of her contemporaries. There really isn't a fictional character or grand conceptual schtick to her tunes. It's just her: a teenager who has seen some heartbreak, hates having her style copped, and uses her angst to write some fine viral pop tunes. Even when she does sing a fictional narrative, as she does on "Bellyache," it's with a tone that falls in line with the rest of her extended play: "I'm biting my nails. I'm too young to go to jail... It's kind of funny," she sings from the perspective of a murderer who regrets having slaughtered her friends and lover just moments prior to the song.

For someone so young, Eilish's swagger is unbelievably convincing. She released Don't Smile at Me at age 15, meaning she threatened to ignite a boyfriend's car and watch it burn on the swelling choruses of "Watch" before she could even drive herself. Her voice is light but is complemented, not hindered, by her brother's production choices, and to boot, their refreshingly casual songwriting is trendy without the overwrought poems many young artists tend to pen in their infancy. After all, Billie Eilish is not here to make you (or herself, for that matter) smile; she's here to make music that sounds badass – and that's exactly what she's done here.

Don't Smile at Me is available now under Interscope Records.