I once met an ex-apple engineer who created a hat that would read your thoughts and play the song you were thinking about. It only worked for certain people and

I once met an ex-apple engineer who created a hat that would read your thoughts and play the song you were thinking about. It only worked for certain people and had a limited playlist to choose from but it was really cool watching your "brainwaves" on a screen and then thinking "Daft Punk Get Lucky" and having it play on the speakers.