Perry gives a sexy over-the-shoulder glance before performing in London. Plus: Lady Gaga, Ashlee, Pete & Bronx, Zac Efron and more


Katy Perry proves to be a bright spot at the Capital 95.8 Summertime Ball – a charity radio concert – Sunday at London's Emirates Stadium, where the singer kicked off the festivities with a set that included her megahit "I Kissed a Girl." Also on the bill: Kelly Clarkson (not pictured).