The age of the times

I have a collection of cassettes from when I studied in Mexico in 1993-1994. Some is music and others are tapes from a radio program that I had with a small handful of other US international students (we called the program Gringolingo, by the way). They were tucked away in a wooden box on a shelf in Ale's room. He was interested in the box so I got it down. When he opened it he was puzzled and asked, "What are those?" He wasn't too interested when I told him. He only knows CDs & DVDs.