Taylor Swift is one of the biggest stars on the planet right now, which means that she presumably has the celeb world at her beck and call.

During her London gig earlier in the year, she brought her group of model friends - Cara Delevingne, Karlie Kloss et all - out for a bit of a schmoozefest in the middle of her set.

On Saturday night, she did the same thing at her gig in California, bringing legendary folk singer Joan Baez and actress Julia Roberts out on stage for no particular reason other than to dance alongside Swift as she performed her song 'Style'.

She later tweeted pictures of the performance, calling both women - who were wearing Taylor Swift t-shirts - 'my heroes'.