Jimmy Fallon always chooses the most appropriate time to unleash his pitch-perfect Neil Young impression on the masses and tonight was no different: Musical guest Bruce Springsteen — making the rounds in promotion of his latest reissue/documentary project — joined the Late Night host for a surprise rendition of Willow Smith’s chart-topping song “Whip My Hair.” Of all the WTFery in this wonderful moment, I must go with: Why is The Boss dressed up as his 1970s self? Let’s not answer that and just let the lulz commence…