So, I’ve begun to notice a trend among the pop girls about the common trajectory of their careers. I first noticed it with the release of Witness, and realised that Katy’s career is pretty much mirroring Gaga’s. Anyway, here it is: An artist will have a huge peak era, this is when they are constantly at the top of the charts, and universally loved. For Gaga this was TFM era, and for Katy this was The teenage dream era.  They will then have the follow up era, which will initially have h