Talent show judge, motormouth, songwriter and all-round vocal acrobat Jessica Cornish – aka Jessie J – arrives in London with a bang to perform her high-energy dance pop and soulful, electronic R&B as part of the iTunes Festival. She is, undeniably, a top performer with a huge pair of lungs and the confidence to match, and will no doubt be performing songs from second album 'Alive', released in October of last year. Supporting Double J is James Bay, a young, acoustic guitar-toting, hat-loving troubadour. Bay sings slow and steady folk numbers like Damien Rice and is a hot tip at the moment. Having sold out his smaller shows, he's on course to make a good impression at this big show. To win free tickets to the iTunes Festival, enter at itunes.com/festival.