Nicki Minaj has been busy, even for Nicki: in the past forty-eight hours, she’s popped up on a new Rick Ross track (“You the Boss”) and a Big Sean remix (“Dance A$$”). But Vulture would like to draw your special attention to the third and, in our opinion, most engaging collaboration that Nicki has released this week: “Fireball,” the new single from Willow Smith. Now, hear us out: Willow is still very young--just shy of 11--and her music is probably still best appreciated at a roller-rink or Chuck-E-Cheese or wherever the preteens have their birthday parties these days. But “Fireball” is a return to form for the youngest Smith; after experimenting with an actual chorus and melody in “21st Century Girl,” she’s gone back to her strength—a short, super-catchy, party-ready refrain that gets repeated over and over and over until you are sure to accidentally start singing it at a social gathering. “I’m the fireball of this party / I’m the fire / I’m the fireball of this party.” You don’t even have to shake your head around for this one. One more thing: are Nicki Minaj and the Smiths actually neighbors, and if so, how does one score an invite to that block party? Just asking for a friend.