.... For example, I love Jim Croce's Operator but when's the last time anyone talked to an operator on a payphone for a dime.... Point being, It's not just slang one has to consider when talking about sounding dated.
A couple of totally unrelated observations....
I'm training with a Search and Rescue team with my dog. One of the things in our certification is a backpack check for a list of items that help us survive in the woods. One of the things on that list is 2 quarters..... so you can make a payphone call to the emergency folks. Supposedly, there was a pay phone on the AT .... but you can't even find pay phones in cities any more. They finally revised the list and removed the 2 quarters and dropped the mandatory backpack check.
I used to play at a club where the owners wife though I looked like Jim Croce. She kept pestering me to sing Time In A Bottle. I never did learn that song.... she used to give me the creeps.
I was taken to task for the word "something" in a song.... they told me I needed to tell what that "something" was......
..............we now return you to your regularly scheduled programming, already in progress.....