Kacey Musgraves and Ariana Grande performed at the 2019 iHeartRadio Music Awards at the Forum in Los Angeles on Thursday night. Musgraves was joined for her rendition of "Rainbow" by Coldplay's Chris Martin. He played piano while she sang from on top of a giant rainbow. Meanwhile, in a pre-recorded performance. Grande sang “Needy” from her recently-released album thank u, next. Watch clips of both performances below.