Swift and Perry have been locked in a quiet feud for years.
Katy Perry - Page 2
Watch and see highlights from Katy Perry's 24-hour 'Witness World Wide' live stream event.
Swift decided that as Perry shared her new album on YouTube via a special event ('Katy Perry: Witness World Wide'), she'd release her entire back catalog on all streaming services.
'I mean, I'm not Buddha,' Perry said.
The Katy Perry: Witness World Wide event offers behind-the-scenes access for fans and promises 'plenty of surprises.'
From subtweets to side-eye to diss tracks, 'beef' is a pop music tradition of the highest order.
Take a look at the album art and track list for Katy Perry's fourth record, 'Witness.'
The Chainsmokers, Lana Del Rey, Little Mix and more also played at the UK fest this weekend.
Watch the 'Stranger Things' star sing 'Ave Maria' and Katy Perry's 'Firework' at a comic convention.
The pop queen sipped from a Starbucks cup and explained that she was extremely jet lagged while launching into one of the weirdest interviews Kemp says he's ever done.