Adele, Swift soar as US digital music sales sing

The overall number of purchases -- music videos, single tracks, or albums -- topped 1.66 billion in a 3.1 percent climb from a record set in the year 2011, according to Nielsen senior vice president David Bakula.

The gain was "driven by digital music sales, which continue be a key growth element within the market," Bakula said.

Sales of digital albums jumped 14.1 percent and track sales were up 5.1 percent.

However, physical mediums still accounted for the bulk of business despite slipping 12.8 percent from the prior year, Nielsen reported.

Compact disks continued to exit the music stage, with sales dropping 13 percent. A retro trend back toward vinyl albums was evidenced by a 17.7 percent surge in sales of music in that old-school format.

"The big artist stories of the year are Adele and Taylor Swift," said Bakula.

Singer Adele's album, "21," is the first album ever to be the top seller of the year for two consecutive years, according to Nielsen.

Swift's album "Red" sold more than 3.1 million copies in 10 weeks, debuting with the highest weekly sales of any title since 2002, Bakula said.