Thirty years ago, in the summer of 1986, hip-hop was not yet mainstream; youth culture but not mass culture. Eighteen-year-old LL Cool J, with his album Radio, was a rare presence on the Billboard pop chart. There was no rap chart yet. But as hot as LL was that year, anyone imagining ahead to 2016 would be more likely to picture jetpacks than LL Cool J hosting a prime-time variety show.

Which is why it was seen back then as a daring move for the city of New York to tap LL to record a public service announcement promoting safe sex to teenagers. My mother, Alice Radosh, ran the Mayor’s Office of Adolescent Pregnancy and Parenting Services at the time. She can not take credit for bringing in the up-and-coming Queens rapper—that idea came from the ad agency donating its time to the cause—but she remembers that he was excited to be a part of it. He knew kids who had become parents too young, and he thought he could reach people like them.

Working with his DJ, the pioneering Cut Creator, LL Cool J wrote and recorded “Smart Sex Rap,” a 30-second track that stands today as a weird but very cool artifact of golden age hip-hop. “Babies makin’ babies, don’t be ill, this is the ’80s. I’m talking to the homeboys and the ladies!”

As my mother recalls it, several radio stations actually refused to air the spot—ostensibly due to rules that PSAs had to be read by station personnel but more likely because a rapper pitching condoms to high-schoolers was simply radioactive. Once the campaign ran its course, Smart Sex Rap was forgotten. LL Cool J, of course, would become one of the biggest hit-makers of old-school rap and a hip-hop icon. As the host and co-creator of Lip Sync Battle, he has recently attracted a whole new audience.

Not long ago, in a box in my mother’s basement, I found an old cassette tape labeled “LL Cool J PSA.” Maybe another copy exists in LL’s archives, or deep in the bowels of Hot 97, but as far as I can tell this is the first time it’s been heard by anyone since summer of 1986.