If Youtube videos do not play reload the page, that's a Youtube bug.
Or maybe now, a few years later, it's a new bug ;-)

Tigran Hamasyan - 37 Newlyweds

Tigran Hamasyan - Levitation 21

Elephant Gym (大象體操) - Quilt (被子)

Elephant Gym (大象體操) - Light (燈)

Elephant Gym (大象體操) - Head & Body (頭,身體)