I was about 12 years old when I got something for my birthday that I was just "dying" to have. It was a pink Bakelite radio. Now I could listen to whatever music I wanted to when I was in my bedroom. It was great because some new band named "The Beatles" were having lots of songs coming on the radio and I liked them.
One of the other fantastic things about this radio was that I discovered that a mystery theater would come on. If I remember correctly, it come on about 9:00 p.m. on Sunday nights. I was supposed to be in bed sleeping, but I would take the radio, place it under the covers with me and then I would put my ear up to the speaker. If I turned it down low enough no one would ever know that I was listening to the radio.
It was exciting and scary to listen to the stories. The sound effects made you feel like you could "see" everything that was happening. I caught myself holding my breath many times for fear that I would miss out of something being said at a very critical point in the story. My favorite one I remember was about a small group of people being trapped in a pyramid in the middle of the desert. (It was like a pre-Indiana Jones movie). I don't remember what happened, but I know it was exciting. I think the stories usually lasted for less than half an hour and then it was time for me to turn the radio off and go to sleep. Sleep didn't come easily sometimes, but I was always back hiding under the covers the next week.
This is a small sampling of an example of what the mystery theater would sound like...