Katy Perry posted behind the scenes footage from the west coast leg of her ‘California Dreams’ Arena Tour 2011. “My idea of success is to get them a great show continuing every night and know that it’s a whole new set of people,” Perry said about her live shows. Katy is seen rehearsing a ‘Friday’ performance with her ‘Last Friday Night (T.G.I.F.)’ video co-star Rebecca Black. Watch it via YouTube below.