How much does the job pay? http://ghettotube.in.net/ ghetto tube  Perry reunited with music producers and songwriters Max Martin, Dr. Luke and Cirkut for "Prism." Most of the 13 tracks, all co-written by Perry, were recorded in San Diego, or with Martin and record producer and songwriter Klas Ahlund in Stockholm, where club anthem "Walking on Air" and the hip-hop tinged "This is How We Do" were both made.