Acoustic Guitar – George Pajon, Jr.Arranged By [Orchestral And String Arrangement] – Onree Gill, will.i.amElectric Bass – Caleb SpeirFeaturing – Dante SantiagoMixed By – Dylan "3-D" Dresdow, will.i.amOrchestra [Orchestral Portions] – The Czech Symphony OrchestraProducer, Drum Programming, Synthesizer, Tambourine – will.i.amRecorded By [Czech Symphony Orchestra], Engineer [Czech Symphony Orchestra] – Michal PekárekRecorded By, Engineer – Padraic "Padlock" Kerin, will.i.amWritten-By – Caleb Speir, George Pajon, Jr., William Adams

Drum Programming – Lazy Jay, will.i.amEngineer [Additional Engineering Of Britney Spears' Vocals] – David Levy , Norm BantomFeaturing – Britney SpearsKeyboards, Programmed By [MIDI Programming] – Lazy JayMixed By – Dylan "3-D" DresdowProducer [Additional], Synthesizer, Bass [Moog Bass] – will.i.amProducer, Recorded By, Engineer – Lazy JayRecorded By [Vocals], Engineer [Vocals] – Padraic "Padlock" Kerin, will.i.amWritten-By – Jean Baptiste , Jef Martens, William Adams

Arranged By [String Arrangement] – Onree GillFeaturing – Baby KaelyHorns – Adam Wolf, John Eagle Mixed By – Dylan "3-D" DresdowProducer – Maejor AliRecorded By [Strings & Horns], Engineer [Strings & Horns] – Ghazi Hourani, Padraic "Padlock" KerinRecorded By, Engineer – Daniel Zaidenstadt, will.i.amStrings – Adrienne Woods, Cameron Stone, Chris Woods , Emily Moore, Ginny Luke, James Klopfleisch, Lucine Fyelon, Neel HammondWritten-By – Brandon Green, Calvin Johnson , William Adams

Featuring – Chris Brown Mixed By – Dylan "3-D" Dresdow, will.i.amProducer, Synthesizer, Drum Programming – will.i.amRecorded By, Engineer – Dustin "Chi" Capulong, Padraic "Padlock" Kerin, will.i.amWritten-By – Artem Stoliarov, Chris Brown , William Adams

Featuring – Juicy JMixed By – Dylan "3-D" Dresdow, will.i.amProducer – Freshm3n III, Poet , will.i.amProgrammed By [Additional Programming] – JakpotRecorded By, Engineer – Mike "Crazy Mike" Foster, Padraic "Padlock" Kerin, Poet , will.i.amSynthesizer, Drum Programming – Freshm3n IIIWritten-By – Darrell Eversley, Howard Eversley, Jaime L. Munson, Jordan Houston, Shaun Spearman, William Adams

Engineer [Assistant, Justin Bieber's Vocals] – Neil TuckerFeaturing – Justin BieberMixed By – Steve DudaProducer, Drum Programming – Damien Leroy, will.i.amRecorded By [Justin Bieber’s Vocals], Engineer [Justin Bieber’s Vocals] – Chris 'Tek' O'Ryan, Josh GudwinRecorded By, Engineer – Damien Leroy, Padraic "Padlock" Kerin, will.i.amSynthesizer – Damien LeroyWritten-By – Damien Leroy, Justin Bieber, William Adams

Arranged By [Strings] – Onree Gill, will.i.amBass – Kevin C. BrandonCello – Miguel Martinez , Peggy BaldwinComposed By [Strings] – Onree GillEngineer [Assistant] – Justin MerrillFeaturing – Eva SimonsHorns – Joseph Meyer, Justin HagemanMixed By – Dylan "3-D" DresdowMixed By [Assistant] – AJ Clark, Jaime MartinezProducer, Synthesizer – Sebastian Ingrosso, Steve Angello, will.i.amRecorded By [Eva Simons' Vocals], Engineer [Eva Simons's Vocals] – Eva SimonsRecorded By, Engineer – Padraic "Padlock" Kerin, will.i.amViola – James Ross, Karen ElaineViolin – Charlie Bisharat, Christopher Woods, Chung Mei Chang, Kathleen Robertson, Lesa Terry, Mark Cargill, Nicole Garcia, Richard Adkins, Susan ChatmanWritten-By – Eva Maria Simons, Max Martin, Mike Hamilton , Sebastian Ingrosso, Steve Angello, William Adams

Drum Programming – Freshm3n IIIMixed By – Dylan "3-D" DresdowProducer – Damien Leroy, Freshm3n III, will.i.amRecorded By – will.i.amSynthesizer – Damien LeroyWritten-By – Damien Leroy, William Adams

Arranged By [Orchestral And String Arrangement] – Onree Gill, will.i.amMixed By – Dylan "3-D" DresdowOrchestra [Orchestral Portions] – Czech Symphony OrchestraProducer – will.i.amRecorded By [Czech Symphony Orchestra], Engineer [Czech Symphony Orchestra] – Michal PekárekVocals [Additional] – Shelby SpalioneWritten-By – Jack Milas, Oli Chang, William Adams

Coordinator [Production Coordination] – Irene Richter, Katie Mitzell, Padraic "Padlock" KerinEngineer [Assistant] – Rachael FindlenFeaturing – Nicole ScherzingerMixed By – Dylan "3-D" Dresdow, will.i.amProducer – will.i.amRecorded By, Engineer – Clint Gibbs, Padraic "Padlock" Kerin, will.i.amWritten-By – Henry Walter, Lukasz Gottwald, William Adams

Drum Programming – Freshm3n III, Michael McHenryFeaturing – 2NE1, apl.de.apGuitar – Alain WhyteKeyboards – Jean Baptiste , Michael McHenryMixed By – Dylan "3-D" Dresdow, will.i.amProducer – Free School , Freshm3n III, will.i.amRecorded By, Engineer – Padraic "Padlock" Kerin, will.i.amSynthesizer – Freshm3n IIIWritten-By – Alain Whyte, Allan Pineda, Jean Baptiste , Michael McHenry, William Adams

Arranged By [Orchestral And String Arrangement] – Onree Gill, will.i.amDrum Programming – Michael McHenry, will.i.amKeyboards – Michael McHenryMixed By – Afrojack, Dylan "3-D" Dresdow, will.i.amOrchestra [Orchestral Portions] – Czech Symphony OrchestraProducer – Afrojack, Free School , will.i.amRecorded By [Czech Symphony Orchestra], Engineer [Czech Symphony Orchestra] – Michal PekárekRecorded By, Engineer – Afrojack, Padraic "Padlock" Kerin, will.i.amWritten-By – Jean Baptiste , Michael McHenry, Padraic Kerin, Ryan Buendia, William Adams

Coordinator [Production Coordination] – Irene Richter, Katie Mitzell, Padraic "Padlock" KerinEngineer [Assistant] – Rachael FindlenMixed By – Dylan "3-D" Dresdow, will.i.amProducer – will.i.amRecorded By, Engineer – Clint Gibbs, Padraic "Padlock" Kerin, will.i.amWritten-By – Henry Walter, Lukasz Gottwald, William Adams

Drum Programming – will.i.am, Zach "gfg" JonesFeaturing – Skylar GreyMixed By – Dylan "3-D" DresdowProducer – will.i.amProducer [Additional] – Zach "gfg" JonesRecorded By, Engineer – Padraic "Padlock" Kerin, will.i.amSynthesizer – Damien Leroy, Zach "gfg" JonesWritten-By – Holly Hafermann, Keith Harris, William Adams, Zachary Jones

Arranged By [Orchestral And String Arrangement] – Onree Gill, will.i.amCoordinator [Production Coordination] – Andrew "Muffman" Luftman, Irene Richter, Katie Mitzell, Padraic "Padlock" Kerin, Scott "Yarmov" YarmovskyEngineer [Assistant] – Rachael FindlenEngineer [Engineered For Mix] – John HanesFeaturing – Miley CyrusMixed By – Serban GheneaMixed By [Additional] – Dylan "3-D" DresdowOrchestra [Orchestral Portions] – Czech Symphony OrchestraProducer – Benny Blanco , Cirkut, Dr. LukeRecorded By [Czech Symphony Orchestra], Engineer [Czech Symphony Orchestra] – Michal PekárekRecorded By, Engineer – Clint Gibbs, Padraic "Padlock" Kerin, will.i.amWritten-By – Benjamin Levin, Henry Walter, Lukasz Gottwald, William Adams