Rascal Flatts, Carrie Underwood and the Dixie Chicks are on the list of the Top 10 best-selling albums for the first half of 2006, according to a report issued Friday (July 7) by Nielsen SoundScan, the company that tracks retail sales of music. The High School Musical soundtrack sold 2.2 million copies for the 26-week period ending July 2 to be the top-selling album so far this year. Rascal Flatts come in at No. 2 with just under 2 million copies sold of Me and My Gang since its release in April. Underwood is in fifth place after selling almost 1.5 million copies of Some Hearts since Jan. 2. Released in November 2005, Underwood's album has sold more than 3 million units. The Dixie Chicks' Taking the Long Way, released in late May, has sold 1.2 million copies to land in eighth place on the list. Thanks in large part to those three albums, country sales have skyrocketed by 17.7 percent over the same period last year to mark the largest increase of any musical genre. Other top-selling albums include titles by James Blunt, Mary J. Blige, T.I., Andrea Bocelli and Nickelback.