Sylvia Westall Javier Blas Fiona Macdonald Bloomberg

On a day that Saudi Arabia jolted the oil market with an output cut it called a "gesture of goodwill," the kingdom's de-facto ruler took center stage in a mirrored concert hall, ready to resolve a different crisis.

On a day that Saudi Arabia jolted the oil market with an output cut it called a "gesture of goodwill," the kingdom's de-facto ruler took center stage in a mirrored concert hall, ready to resolve a different crisis.