NASHVILLE, Tenn. — The soundtrack album for the hit Disney Channel musical "High School Musical" was the top-selling CD in 2006, according to figures released by Neisen Soundscan.


The album, featuring songs by the stars of the film, sold more than 3.7 million copies, while the hit country music trio Rascal Flatts' "Me and My Gang" was No. 2 in 2006 with more than 3.4 million units sold.


Rascal Flatts was the top-selling artist overall last year with sales of nearly 5 million albums, Neilsen SoundScan said. The group also sold nearly 4 million digital tracks.


The third bestselling album of the year was "Some Hearts," the debut album from "American Idol" winner-turned-country music star Carrie Underwood.


Albums by rockers Nickelback and pop singer Justin Timberlake came in fourth and fifth, respectively.


Overall U.S. album sales dropped by almost 5 percent from 2005, but digital track sales increased by 65 percent.


Country album sales dropped by less than 1 percent.