LOS ANGELES, Sept. 3 — The world’s largest recording company said Wednesday it would slash wholesale CD prices in hopes of reviving music sales, which have dropped 31 percent industrywide in the last three years. UNIVERSAL MUSIC GROUP said it would cut the suggested sale price on a majority of its CDs by $6 to $12.98. The company hopes retailers will follow its lead and drop their CD prices to around $10 or less. The price changes would go into effect by Oct. 1. “We expect (this) will invigorate the music market in North America,” UMG Chairman and...