Watch: #TaylorSwift, #ArianaGrande #JimmyFallon, #Prince And More Perform At #SN40 After-Party

“Saturday Night Live” celebrated its 40th anniversary on Sunday with tons of celebs and some of them performed at the after-party held at New York's Plaza Hotel. Jimmy Fallon kicked off the festivities with an all-star Blues Brothers performance featuring #PaulMcCartney, Taylor Swift, #JimBelushi and #DanAykroyd. #MileyCyrus, Ariana Grande and #DebbieHarry also joined in before Prince hit the stage and got everyone from #BillMurray to #ChrisRock dancing. Watch below.

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