Did Katy Perry Steal A Song? A Forensic Musicologist Weighs In Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email In this Sept. 16, 2014 file photo, Katy Perry performs on stage at "The Prismatic World Tour" at the Honda Center in Anaheim, Calif. ( John Shearer/Invision/AP, File ) Produced by Isabel Angell Hosted by Tanzina Vega Produced by GBH, PRX and WNYC Studios