Watch Lorde and Addison Rae join Charli XCX and Troye Sivan onstage in New York

Lorde and Addison Rae were unveiled as special guest performers during Charli XCX‘s and Troye Sivan‘s joint ‘Sweat’ concert in New York last night (September 23) – watch fan-shot footage of the performances below.READ MORE: It’s Charli XCX’s world and we’re just living in it: a timeline of ‘Brat’ summer so farLast night, XCX and Sivan brought their co-headlining ‘Sweat’ tour to Madison Square Garden in New York. In past