20 years ago today Juvenile dropped his classic album “400 Degreez”

In the fall of 1998, a 23-year-old rapper named Juvenile had erupted out of nowhere — or, more specifically, out of the CJ Peete housing projects in New Orleans — with a song so profoundly, overwhelmingly Southern that it felt like a transmission from some other, much funkier alien civilization. Over a beat that sounded like an evil robot’s spicy-food-before-bed nightmare, Juvenile, his New Orleans drawl a mile deep, mercilessly clowned some mysterious, all-pervading “you.” The “Ha” of the title wasn’t a laugh. It was a James Brown grunt, a simple verbal emphasis: “You brought our tape with a check, ha / You wearin’ a vest, ha / You tryin’ to protect your chest, ha.”

The song’s music video, from director Marc Klasfeld, turned Juvenile’s New Orleans into a whole world unto itself. It’s a visual tone poem, a meditation on snakes and boarded-up houses and above-ground graveyards and neon-color Porsches and ambulance lights and air-conditioner sweat and yellowing eyes. Juvenile wears crispy white clothes and stands in puddles, staring the camera down. The video shows such a collision of money and desolation that your brain can get whiplash just watching it. It’s fascinating and immersive and overwhelming, and it remains one of the best music videos ever made.

In the 20 years since its release, rap music has internalized all these anarchic regional trends, and it’s harder for someone like Juvenile to come along and shock the world. But in the moment, that’s what he did. Juvenile was a compelling figure with a homegrown sound, a new-to-us accent, and a whole lot of urgency in his delivery. He made a great album, and he changed everything.