London

The capital of England and the United Kingdom, and one of the most historically consequential cities ever built. London was the center of the British Empire at its peak, which means it was effectively the administrative capital of a quarter of the world's land surface. That colonial history left London permanently multilingual, diverse, and culturally layered in ways that continue to generate both creative energy and unresolved political tension. Its contributions to music -- Bowie, the Stones, punk, grime, drum and bass -- are disproportionate to any single city's reasonable share. It remains one of the world's top financial centers.

Added by @jamesobrien