Country sales are having a good year. The genre has accounted for 11.8% of all album sales through July 5, an increase from 10.3% last year, according to Nielsen SoundScan. Digital sales are up as well, to 11.5% of all country album sales from 7.8% last year.

But, those numbers change quite a bit when you remove the sales of the "Hannah Montana: The Movie" soundtrack - the album falls under the country category - from the tally. Without the album, country's share of total market sales drops seven tenths of a point to 11.1%. Take out "Hannah" and country's share of total CD sales drops to 12.6% from 13.4% while its share of digital share drops to 6.0% from 6.3%. Since digital accounts for about 11% of "Hannah" sales, country's digital-to-total albums ratio is roughly the same without "Hannah."

Although the "Hannah Montana: The Movie" soundtrack is classified as country, previous Hannah Montana or Miley Cyrus albums are all classified as pop. Cyrus’ songs on the soundtrack, as well as a track by Steve Rushton, are pop songs. But the soundtrack includes Taylor Swift’s “Crazier,” acoustic versions of Rascal Flatts’ “Backwards” and “Bless the Broken Road” and “Back to Tennessee” by her father, Billy Ray Cyrus.

The genre of a superstar artist has a material impact on that genre's market overall share. This was the case with The Eagles' "Long Road Out of Eden," the band's 2007 Wal-Mart exclusive that was classified as country. To date, "Long Road Out of Eden" has sold 3.3 million units. In its 15 weeks of release, "Hannah" has sold 1.2 million units.