Remember when gangsta rap and heavy-metal bands dominated the top of the charts? The No. 1 album in the United States this week is the soundtrack to “High School Musical,” the Disney Channel original movie about a shy, studious girl and a popular basketball player who find young romance through their tryouts for a campus stage production.

The soundtrack sold 142,000 copies for the week to claim the best-seller spot on the charts compiled by Nielsen SoundScan’s retail reports.

“High School Musical” has sold 812,000 copies to date, and not only do the main characters in the movie meet while singing karaoke, the soundtrack CD comes with karaoke instrumental versions of the two most popular songs, “Breaking Free” and “Start of Something New,” so the kids can sing along at home. The movie has been getting plenty of air time on the Disney Channel, and after debuting at No. 143 on the charts two months ago, “High School Musical” has graduated to become the sleeper hit of 2006.

Last week’s No. 1 album, James Blunt’s “Back to Bedlam,” finished No. 2 this week with sales of 126,000 copies. That’s a 22 percent drop from his prior-week sales, which surged after the British singer’s appearance on “The Oprah Winfrey Show” to perform his melancholy song of infatuation, “You’re Beautiful.”

At No. 3 is the week’s top debut, “My Ghetto Report Card” by E-40, the San Francisco Bay Area rapper whose lead single, “Tell Me When to Go,” was produced by Lil John. Juelz Santana, Too Short and Mike Jones are among the hip-hop notables who lend a hand.