Despite efforts by record executives to stanch declining CD sales by releasing a cavalcade of big-name artists during the critical Christmas shopping season, early sales figures show an already struggling industry may now be in even worse shape. In the five weeks since mid-November, when the record labels began their biggest holiday blitz in recent memory, compact disc sales were down 12.9 percent compared to the period in 2001, according to data from Nielsen SoundScan, which tracks music sales. That poor performance comes even as new CDs from artists like Shania Twain, Mariah Carey, Jay-Z and Paul McCartney have sold...