Didi Beck  Didi Beck is a German electric bass and double bass player. He plays in the rockabilly band, the Boppin'B. An accomplished upright bass slap bass player, he teaches slap bass and has written an instruction book on slapping, and a made a video entitled "How to Learn the Rockabilly Slap Bass Starring Didi Beck". His rapid, virtuosic slapping technique can be heard online.