Tunes of the Wierd

I was listening to a story on one of our local NPR stations yesterday, and they were talking about a strange humming sound that can be heard on Vashon Island by some of the residents. At the end of the piece, they used the theme from The X-Files as the outro music.

Now, when I was growing up, such a piece would have been accompanied by the theme from The Twilight Zone, and that prodded me to think about the transition. I couldn't tell you when it occurred, but I realize that by now, it's more or less complete. Were I to be speaking to my niece about some strange happenstance, and start whistling The Twilight Zone, the poor child would be completely baffled, even though my sister would immediately recognize it. I'm curious to know what that cutoff is. And now I wonder if there wasn't some old radio show tune that The Twilight Zone knocked from its cultural perch.