Vinyl records. They were very much on their way out when I was just old enough to have music that I listened to on my own... but I did have a record of sesame street songs that I loved as a child. As a slightly older child, I learned to mess with the speed settings and, via manual rotation, the direction of the record player. I learned to hear my favorite sesame street characters sing like they were on crack... 50 feet tall or possessed...respectively.