• 
  Gavin Rossdale

  Self
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  John Rhys-Davies

  General Haig
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  Katharine McPhee

  Self
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  John Debney

  Self
• 
  Hugh Bonneville

  Narrator
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  Robert Cait

  Burt McMurtrie
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  David Foster

  Self
• 
  Siedah Garrett

  Self

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  Anggun

  Self
• 
  Josh Groban

  Self
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  Randy Jackson

  Self
• 
  Kelly Clarkson

  Self
• 
  Joss Stone

  Self
• 
  Shelea Frazier

  Self
• 
  Hannah Friedman

  Self

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  Kevin Michael Moran

  Richard Ranaghan
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  Ailee

  Self
• 
  Rolando Villazón

  Self
• 
  Lina Makhoul

  Self