iBT TOEFL Topic Vocabulary Breakthrough Unit 033

iBT TOEFL Topic Vocabulary Breakthrough Unit 033
Author: Li Xiaolai

33. Pitch depends upon the rate of vibration, or frequency, of sound waves that produce a particular tone. Most Western music was based on 12 equivalent intervals per octave; however, a great deal of Western folk music conforms to pentatonic scale, the best-known form of which contains no half steps.

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