Singers celebrate collaboration's Grammy nomination for Best Pop Duo/Group Performance at latest Eras Tour gig
The singer also surprised fans with an appearance from Gracie Abrams; the pair debuted their collaboration "Us" live
Singer, whose debut LP Good Riddance arrived Friday, previews her special guest spot of Taylor Swift's The Eras Tour
Plus, Swedish duo NOTD team up with Memphis rockers The Band CAMINO for summery track
