4899
His introduction to the world of popular music was around the age of 10 , listening to rock operas such as " Jesus Christ Superstar " and " Hair " , and other material that was midway between classical and popular music .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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