* Written language: Crucial for record-keeping, communication over distance, and the development of complex ideas.
* Domestication: Allowed for a stable food supply, surplus resources, and the development of settled communities.
* Social hierarchy: Organized societies and facilitated decision-making and resource allocation.
* Specialization: Enabled the development of skilled labor, increased efficiency, and innovation.
While music is a powerful element of human culture and has played a significant role in many civilizations, it's not a fundamental *key* to the development of civilization in the same way as the other options.
Let me know if you have any other questions!