I was a teenager in the 1980s and, growing up in West Virginia, I didn't have a lot of access to music beyond the radio. My very small town didn't have a record store, and my cable company didn't have MTV, so I relied on my SPIN subscription, TBS' Night Tracks, and occasional trips to the closest city (Roanoke, VA) to hit record stores, to discover new stuff. I did OK given all that, and listened to REM and The Smiths and other more widely known "college rock" groups of the time, with my finger as close to the pulse as I could get it.
I also had John Hughes movies. He seemed to have his ear to the street, both with the way teenagers talked and what they listened to, at least the teenagers who lived in big cities (or cool suburbs, like Shermer, IL) that had access to cool record stores. I remember watching the credits to Sixteen Candles on VHS -- the tiniest font made worse on our small TV -- and wrote down "The Revillos," "Oingo Boingo" and "The Specials" and then waiting two weeks to go to a record store to see if they had anything. Soon after that, thanks to The Breakfast Club giving Simple Minds their first US hit, John Hughes movies became a thing to look forward to for the music, both the actual soundtrack albums but also all the other songs that were in them. Even the posters on the wall: I bought records by Cabaret Voltaire and Easterhouse because Matthew Broderick and Eric Soltz had them on their walls, respectively, in John Hughes movies. And when the Ferris Bueller's Day Off soundtrack was never released (despite their being a mention of it in the end credits), I went on a 10-year hunt to track down all the songs used in it, which was not easy -- what songs weren't recorded specifically for the film (and never released) were often obscure b-sides.