The trick you are referring to is commonly known as the "YouTube Mind Reading Trick" or the "Phone Browser Trick." While I don't have access to specific details or the exact method behind the trick, it typically involves a combination of pre-planning, sleight of hand, and technology manipulation. The magician may use a hidden device or a cleverly designed website to create the illusion of mind-reading and playing the spectator's chosen song. It's important to note that the specifics of such tricks may vary among different magicians, and revealing the exact workings behind the trick would spoil the magic.
mybkexperience Enjoy the wonder and mystery of the performance!