Last time you listened to music, was it radio? Recorded (i.e. a disc, vinyl record, other media)? Or streaming?
For a while, here’s how radio PLAYED music: the magnetic tape cartridge, commonly known as carts. These babies held jingles, commercial spots, bits of sound used for comedy, news soundbites, and, in some radio formats, the songs were stored on them for convenience.
Durable, easy to handle, usually reliable. Now, almost completely forgotten.