World rhythms; Iron Maiden is a Japanese hit. Whitney Houston is a British favorite. Get ready to rock around the time zones.

WORLD RHYTHMS

Ever since Chuck Berry asked Maybelline, "Why can't you be true?" rock music has been dominated by English-language acts. Rock continues to sell best in English-speaking regions of the world: the United Kingdom, Northern Europe, and especially the melting pot of pop rap, hardcore punk, and head-banging heavy metal--the United States.

After years of flat unit sales, rock marketers hope to extend their reaches beyond the West. But their two newest targets--the Soviet Union and China--won't be easily cracked.

"If the Soviet market ever opens up, it will be a major opportunity--all the kids have been starved for this stuff," says Steve Pritchitt, PolyGram's vice president for international promotions. China's young population also is poised for new music. More than half of the country's one billion people are under age 30.

The market for rock music in Eastern Europe and Asia depends upon increasing cultural openness. In the past, both the Soviet Union and China have taken a dim view of Western rock's emphasis on rebellion and sexual freedom.

TROUBLE ON THE HIGH SEAS

Legitimate markets for rock music are springing up in countries that once thrived on huge pirate markets--countries like Greece, Turkey, Indonesia, Malaysia, and Taiwan.