In a previous post on contemporary styles of music, we noted our intention of developing a new class, 781.648 Electronica, which is now present in DDC 23. The close association of electronica and dancing makes 781.6481554 (built with 781.648 plus 1 General principles from the table under 781.63-78.69 plus 554 Dance music from 781.554 Dance music) redundant; a do-not-use note indicates that that number is not valid. A work like All music guide to electronica would now be classed in 781.648.
In Table 1, festivals have been relocated from 1—079 Competitions, awards, financial support to 1—074 Museums, collections, exhibits, where festivals are now listed in the class-here note. A work on the subject of the USA Today article, electronica fests, would thus be classified in 781.648074 Electronica festivals.