You've heard of 3D, and even 4D, but prepare yourself for 8D. Well, sort of.
If YouTube is your main source for music streaming then you may have seen something called "8D audio" in your suggestion bar.
8D audio is essentially an effect applied to a stereo track where songs have been edited with spacial reverb and mixing to make it seem like the audio moving in a circle around your head. This experience can only be achieved by wearing headphones, which the gimmick relies upon to create the illusion of a 360 degree space.