After a couple of months of travelling i started working on an IOT device that i wanted but no one made it. It was a radio with 3 knobs but instead of channels it had emotions on dial. First dial controlled volume, second happiness and third energy.
A psychology research paper from 1980 by James russell explained how human emotions can be mapped on a 2d chart, when combining this knowledge with the spotify song analysis data it worked like magic. To account for musical taste of each user i added a button to skip songs you don’t like and the radio will tune future song selection to your liking.