How to control iTunes with headphones
If you own headphones with a built-in remote, such as those that come with the iPhone (or these), you can control iTunes directly from the button when it’s plugged into your Apple laptop.
To launch iTunes, press the button once.
To play/pause, press the button once.
To skip to the next track, press the button twice.
To go back to the previous track, press the button three times.
Amazing, I know.
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