Pop Smoke’s “Welcome to the Party” had already been oozing out of cracked car windows in the rapper’s native Brooklyn for an entire summer, and by September the song had drifted all the way to Wisconsin, where a friend of mine who lives near a grain silo sent me a breathless text message: “I just heard Pop Smoke for the first time . . . he sounds like an entire planet rapping.”

What a perfect description. Pop Smoke’s voice was a massive, curvy, cosmic thing, cooler than 50 Cent’s and deeper than God’s. With his heaviest syllables delivered in an exquisite rasp, the friction in Pop Smoke’s throat sounded low and inevitable, like two plates fulfilling their tectonic destiny in a subterranean grind. It’s the kind of sound you feel beneath your feet, but also with your entire body, as if its gravity were connecting you to reality.

So when news spread online Wednesday that this incredible voice had been silenced forever, everything felt suddenly out of balance. Pop Smoke — the 20-year-old rapper born Bashar Barakah Jackson — was fatally shot during a home invasion in Los Angeles, mere days after news that his latest album would debut in the Billboard top 10 and less than two weeks before he was scheduled to embark on a national headlining tour.

What would his tour have sounded like, seeping across the map from nightclub to nightclub? On that new album, “Meet the Woo 2,” Pop Smoke offered an unambiguous clue in four quick words: “I shake the room.” Pithy and profound, that elegant little brag describes rap music itself: a declaration of self, a consecration of community and, fundamentally, a physical event.

At 20, Pop Smoke had already reached a level of self-awareness that most musicians spend lifetimes questing for. He understood himself as a sound.

Rap taxonomists have branded Pop Smoke’s sound as “Brooklyn drill,” a stylistic cousin to the woozy gloom of “U.K. drill” and the hard edges of “Chicago drill.” But whatever you called it, his music was part of a dialogue that flowed across borders, proving that today’s neighborhood anthems can become tomorrow’s international hits. His proudly Gotham sound wasn’t just planet-sized. It was global, too.

And it’s really the celestial bigness of his voice — more than his imminent fame, even more than his youth — that makes Pop Smoke’s death feel so unfair, so unreal. Somehow, this planet becomes more cruel. And it keeps spinning.