As her Lifetimes tour hits the UK, we pick the high points from one of pop’s most successful vocalists, from angsty ballads to empowerment anthems
There’s no getting around the fact that Katy Perry’s breakthrough single has not aged well in some ways – the lyrics are like a lads’ mag reader’s idea of female bi-curiosity – but musically it’s an impressively fizzy retooling of the early-70s low glam sound, with crunchy guitars and glitterbeat drums.