This drum & bass tune is written in a 14-note microtonal temperament. Next Xen is a compilation album that unshackles music from a 200 year old ball and chain. Western music theory says that there are 12 equal notes, and for some reason it's a taboo to break out of this. But what if you want to hear 13? Or even 100 notes, all of different sizes? Such music would be called microtonal, xenharmonic, or just "xen."