Instruments – Greg WellsMixed By – Greg WellsProducer – Greg WellsRecorded By – Luke TozourWritten-By – Katy Perry

Drums – Josh FreezeEngineer [Drums] – Mike FennelInstruments – Ted BrunerMixed By – Joe ZookProducer – Ted BrunerRecorded By – Ted BrunerWritten-By – Katy Perry, Ted Bruner

Bass – Dr. LukeCoordinator – Gary "G" SilverDrums – Benny Blanco , Dr. LukeEngineer – Emily Wright, Nick Banns, Sam Holland, Tatiana Gottwald, Tina KennedyEngineer [Mix] – John HanesGuitar – Dr. Luke, Max MartinMixed By – Serban GheneaMixed By [Assisted By] – Tim RobertsProducer – Dr. LukeProducer [Additional] – Benny Blanco Programmed By – Benny Blanco , Dr. LukeWritten-By – Katy Perry, Lukasz Gottwald, Max Martin

Coordinator [Aerowave Coordinator] – Stephanie KubiakGuitar – Dave StewartInstruments – Dave StewartMixed By – Joe ZookPiano – Katy PerryProducer – David StewartProgrammed By – Ned DouglasProgrammed By [Additional] – Jeff BovaRecorded By – Bill Malina, Ned DouglasWritten-By – Dave Stewart, Katy Perry

Drums – Darren DoddInstruments – Butch WalkerKeyboards – Dan ChaseMixed By – Joe ZookProducer – Butch WalkerProgrammed By – Dan ChaseRecorded By – Paul HagerWritten-By – Katy Perry

Instruments – Greg WellsMixed By – Joe ZookProducer – Greg Wells, Katy PerryRecorded By – Greg WellsWritten-By – Andreas Carlsson, Desmond Child, Katy Perry

Guitar – Dave Katz, Sean GouldMixed By – Joe ZookProducer – SAM, SluggoProgrammed By – Dave Katz, Sam HollanderRecorded By – Sean GouldWritten-By – Dave Katz, Katy Perry, Sam Hollander

Instruments – Greg WellsMixed By – Joe ZookProducer – Greg WellsRecorded By – Greg WellsWritten-By – Greg Wells, Katy Perry

Bass – Paul BushnellDrums – Josh FreezeGuitar – Dave Levita, Scott CutlerMixed By – Joe ZookProducer – Anne Preven, Scott CutlerRecorded By – Doug BoehmWritten-By – Anne Preven, Katy Perry, Scott Cutler

Drums – Darren DoddInstruments – Butch WalkerKeyboards – Dan ChaseMixed By – Joe ZookProducer – Butch WalkerProgrammed By – Dan ChaseRecorded By – Paul HagerWritten-By – Katy Perry

Backing Vocals – Cathy DennisBass – Dr. LukeCoordinator [Production] – Gary "G" SilverDrums – Benny Blanco , Dr. LukeDrums [Live] – Steven WolfEngineer – Aniela Gottwald, Emily Wright, Mike Caffrey, Nick Banns, Sam Holland, Tina KennedyEngineer [Assisted By] – Kitty PurryEngineer [For Mix] – John HanesGuitar – Dr. LukeMixed By – Serban GheneaMixed By [Assisted By] – Tim RobertsProducer – Dr. LukeProducer [Additional Drums] – Mike CaffreyProducer [Additional] – Benny Blanco Programmed By – Benny Blanco , Dr. LukeRecorded By [Drums] – Mike CaffreyWritten-By – Cathy Dennis, Katy Perry, Lukasz Gottwald, Max Martin

Arranged By [Horns] – Jerry HeyBass – Greg WellsGuitar – Greg WellsHorns – Bill Reichenbach , Dan Higgins, Gary Grant, Jerry HeyMixed By – Joe ZookPercussion [Beats] – Greg WellsPiano – Greg WellsProducer – Greg WellsRecorded By – Drew PearsonVocals – Katy PerryWhistling – Katy PerryWritten-By – Greg Wells, Katy Perry