In the week ending Dec. 25, digital track sales jumped nearly 2 million units to almost 9.6 million downloads. For the first time since the mid-1980s, merchants must contend with a multiformat busines

In the week ending Dec. 25, digital track sales jumped nearly 2 million units to almost 9.6 million downloads. For the first time since the mid-1980s, merchants must contend with a multiformat business. Many are closely watching how the majors handle this shift. Read Ed Christman's column.