Music for teenagers lives in dualities and extremes — songs about love so intense, it curdles into hate; songs about pain so deep, only destruction and drugs offer amelioration. Rapper-singer Juice WRLD, who just turned 20, is the latest in a long line of musicians who alchemize these emotional EKGs into pop songs.

The most extreme duality of his Saturday night show at Echostage? How about the onstage “promposal” the DJ followed up by instigating a “f--- love” chant?

That attitude is the electric current that powers Juice WRLD’s music. Over a fusion of skittering hip-hop beats and melancholy guitar chords, Juice groaned and howled melodies that owe more to millennial emo-punk bands like Taking Back Sunday and Fall Out Boy than contemporaries like Chief Keef.

Like those bands’ songs, Juice’s lyrics are brimming with misogyny that points fingers at women and not at the failings of teenage boys. Sometimes, like on the impossibly catchy “All Girls Are The Same,” his lyrics have the banality of tear-stained diary pages: All girls are the same/ they’re rotting my brain, love/ Think I need a change/ Before I go insane, love.

Too often, Juice doesn’t just reduce women to objects of desire and scorn, but into targets for vitriol with a violent edge. On “Fine China, he rapped: It’s her body or nobody, I refuse to compromise/ So if she leaves, I’ma kill her, oh, she’ll die.

Juice’s lyrics move beyond teenage immaturity into dangerous territory, particularly in light of a recent United Nations study that found that about 58 percent of the roughly 87,000 women killed by homicide worldwide last year were murdered by partners or relatives.

Sadly, these lyrics are nothing new for emo troubadours.

Indeed, the work of third-wave emo bands has been reappraised in the #MeToo era, and while Juice WRLD might just be penning violent fantasies, he gave cover to an artist whose actions spoke louder than words.

After a rundown of contemporary rappers who died young, Juice entreated the crowd, “Say we love you X,” in reference to XXXTentacion, the rapper with a particularly gruesome history of violence who was murdered in June.

Neither his lyrics nor the tribute to XXXTentacion gave pause to the capacity crowd of teens and preteens, who were almost uniformly white and mostly male. From the opening set on, the entire audience jumped, danced, moshed, made out and thrust their phones in the air, as a few courageous parents looked on from safe distances.

If this seemingly suburban horde had been born 20 years earlier, they would have been doing the same at emo-punk shows. In that way, how Juice WRLD dramatizes and exaggerates teen-boy heartbreak is nothing new or uniquely vile. But at this time, coming from a scene that spewed out XXXTentacion and similarly abusive acts like 6ix9ine, the leash is getting shorter.

For new artists mining this territory, time’s up.