This is a small radio / boombox, the kind of thing that litters the beaches during the summer. As you examine it, you notice a few cassette tapes stacked next to it. You can't find any commercial tapes - they are all blank.
One of the cases is empty. It is marked "Carlie's Killer Playlist for Roderick," with a track listing written in a distinctly feminine hand. It looks like the tape is loaded.
Play the mix tape
Leave the radio alone