tune in = to listen to radio or view a broadcast --> comes from the act of tuning, when you have to adjust the dial to get to the correct station number drop out = to stop doing something, specifically a race, competition, or school --> used weirdly in this sentence, if im honest decoded sentence, maybe: Use the mp3 play and fm radio to listen to the radio station and stop what you're doing to enjoy time offline.

It is a reference to a sort of slogan or catchphrase from the 1960s. The full phrase is "Tune in, turn on, drop out." It is a familiar phrase to people who lived through the 1960s. It was coined by Dr. Timothy Leary. He had a Ph.D. in clinical psychology and was a Harvard professor. He advocated the use of psychedelic drugs such as psilocybin and LSD. He got in trouble for violating ethics rules in his research projects. "Tune in" means "become aware of psychedelic drugs." "Turn on" means "begin taking them and experiencing higher consciousness." "Drop out" means to unlink yourself from society's stifling norms so that you can embrace and accept the truths of the drug experience... or something like that. I don't know the source of your quotation. It sounds to me like an advertisement. By referencing the Leary quotation, the ad might be suggesting that their MP3 player will be almost as inspiring as a drug trip. They want to suggest that they are hip to the drug scene and their MP3 player is perfect for grooving to psychedelic music.