I have come up with an idea about a new type of mp3. A microchip with a mini antenna is built into the applicants brain via surgery.
The idea is that whenever somebody wants to listen to a song, they just think about it and the microchip activates and starts playing the song.
When they want the song to stop, they just think "stop" and the song will stop. If they want to change the song, they just think of a new song and it will automatically start playing.