The music business is hurting, but you wouldn’t know it from the avalanche of activity between now and Christmas. Despite the boffo business done this summer by Coldplay and Lil Wayne, the industry’s conventional wisdom still holds that the run-up to the holiday season is the best time for major-label singers and rappers to sell CDs (or digital albums). Along with the high-profile releases (described below) from Beyonce and Taylor Swift, there’ll be plenty more, from rapper T.I. (“Paper Trail,” Sept. 30), Jennifer Hudson (self-titled, Sept. 30), John Legend (“Evolver,” Sept. 30), Bob Dylan (the outtakes collection “Tell Tale Signs,” Oct. 7), and Fall Out Boy (“Folie a Deux,” Nov. 4).