Here's my itinerary and should i apply for my china visa from US or in Singapore?

Hi, I am living in NY and will be traveling to Beijing/Shanghai sometime in mid june.

NY --> Singapore (6 - 19 June)
Singapore --> Beijing/Shanghai (21 - 23 June)
Beijing/Shanghai --> Hong Kong (23 - 27 June)
Hong Kong --> Singapore (30 June - 31 July)
Singapore --> New York (1 Aug back to NY)