Eight years after its last album, AC/DC has come back with a bang. "Black Ice" (Columbia), released in an exclusive deal with Wal-Mart, reached No.1 on the U.S. Billboard chart with 784,000 copies sold, the second-biggest sales week for an album this year (after Lil Wayne's "Tha Carter III" in June), according to Nielsen SoundScan. The soundtrack to "High School Musical 3: Senior Year" (Disney), also released last week, reached No.2 and T.I.'s "Paper Trail" (Atlantic) dropped one spot to No.3.