You shouldn't play music that could annoy others.
Janine is riding the bus to work.
Janine wants to listen to some music.
Janine takes out her phone and listens to her favorite song with her earbuds.
Janine pulls out her phone and listens to her favorite song through the speaker.
Janine is able to enjoy some tunes and the other passengers are undisturbed.
The other passengers are disturbed because they can hear and give Janine dirty looks.