As expected, the year-end Nielsen Soundscan numbers once again tell a tale of an industry in turmoil. Album sales in the United States fell 12.8% to 326.2 million units from 373.9 million units in the prior-year, as the sales of CDs fell by nearly 20% for the fourth year in a row.

In the digital realm, growth of individual track sales continued to slow, barely managing to eke out a 1% increase.

Digital album downloads fared better, posting a 13% growth over 2009 figures.

On a more positive note, five tracks topped 4 million units in 2010 (versus four songs in 2009).

The top-selling song, Katy Perry's "California Gurls" scanned nearly 4.4 million units, which compared to 2009 would have ranked third.

The best-selling album of 2010 was Eminem's "Recovery" with 3.4 million units scanned.