IB on alt bands crossing to Pop

THE "WAIT" IS OVER: We may be in the midst of a major shift in the Top 40 format, with a growing number of Alternative Rock records on the air and competing for spins, notes HITS industry insider I.B. Bad in his latest column, posting Friday morning. The next rock band to cross following Gotye, fun., The Lumineers, Of Monsters and Men and Imagine Dragons will be Mumford & Sons, whose "I Will Wait"is catching fire. (1/17a)