There aren’t too many DJs—old-school DJs, not the people who keep you dancing at the club—who require your attention. Back in the day, they usually played the tunes and stayed out of the way, making their mark only on the memories of local listeners. But over the decades, a few managed to create a cultural impact. Let’s take a look at one of them now.

Casey Kasem worked at radio stations all over the country in the 50s and 60s before launching the show for which he is best known, American Top 40, on the 4th of July, 1970. What began as a weekly radio program counting down the biggest hits in the land eventually made its way to TV in the 80s, and Kasem became the face—in addition to the voice—of American popular music. (Ryan Seacrest took over the show in 2004.)

Kasem didn’t choose the music he played—that was determined by sales and radio airplay—but he was a font of information for nascent music geeks, filling each program to the brim with stories and trivia about the songs and artists.

Once he arrived on television—like MTV would do a few years later—Kasem brought musicians right into your living room, providing access like never before to your favorite artists, as well as unknown acts. He also brought an unprecedented level of suspense to the Billboard charts, making you care deeply if a song dropped six spots and out of the Top 10.

His is truly a unique voice — and it all started 43 years ago today. As Casey always said upon signing off, “Keep your feet on the ground and keep reaching for the stars.”

Here’s the opening to his first show in 1970:

Unfortunately, there are no examples of his TV show, but here’s another radio episode, this one from 1984:

And finally, it’s entirely possible you’ve never heard the name Casey Kasem, or seen his face—especially if you’re younger or don’t live in North America—but it’s likely you’ve heard his voice at some point:

Kasem has voiced Shaggy on Scooby Doo since its beginning in 1968.