9493
The album was the first piece in popular music to incorporate the Electro-Theremin , an easier-to-play version of the theremin , as well as the first in rock music to feature a theremin-like instrument .
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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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