The Bad Blood hitmaker was performing the latest show on her 1989 tour when she was joined by Dixie Chicks star Maines for a performance of her band's hit Goodbye Earl.

For Swift, who grew up listening to the country band's hits, it was evidently an emotional moment as she later wrote on Twitter.com, "I used to sing Dixie Chicks songs at every talent show. Singing 'Goodbye Earl' with Natalie tonight was unbelievable."

Also joining her onstage was rocker Morissette, who Swift praised for inspiring her as a young musician. Before duetting with the star on a version of the her 1995 hit You Oughta Know, Swift said her collaborator "defined the music of her decade" and had "inspired a generation of confessional, female singer-songwriters."

After the gig, Swift added on Twitter, "Tonight. 'You Oughta Know'. @Alanis. I don't know how to process how amazing she was. Just absolutely magnificent."