Artist: Christina Aguilera - Producer: Gary Barlow - Mixer: Manny Marroquin - Assistant Mixer: Chris Galland - Assistant Mixer: Ike Schultz - Mastering Engineer: Miles Showell - Strings: London Session Orchestra - String Arranger: Wil Malone - Strings Contractor: Perry Montague-Mason - Engineer: Jon Bailey - Strings Contractor: Isobel Griffiths - Strings Contractor: Susie Gillis - Engineer: Oscar Ramirez