Where I discuss the various forms of synesthesia, a disorder where two senses collide, such as music and color. 

It is not quite common, only a small percentage of people have synesthesia, or various forms of it. However, there are several forms of synesthesia and if you think you might have it, go check out Good Mythical Morning's video on synesthesia. Just type in GMM Synesthesia or Rhett and Link synesthesia and it should link you right to the test!