All of the above. Octave duplication is a common technique used in music from various cultures and countries around the world.
Are you confident in this answer? And if so, can you explain why?
I am confident in this answer because octave duplication is a basic and fundamental concept in music theory that is present in various musical traditions across the globe. It is used to create harmonic and melodic interest by reinforcing or emphasizing a particular pitch or musical line. This technique is not limited to any specific culture or country, as it is a universal concept that can be found in different styles of music worldwide.
