(Pronounced "one-three-eight") A sub-genre of trance that began as an off-hand joke on Armin Van Buuren's A State of Trance radio show, and has grown to be an often-featured genre on the show. The number is the BPM tempo at which the music is played -- somewhat faster than most trance styles. 138 is a "faster, louder trance", in van Buuren's words. He has gone so far as to establish a label specifically for the genre, Who's Afraid of 138?!