Charlie Bisharat, Lucia Micarelli, Dan Higgins, Daphne Chen, Timothy Loo, Bill Reichenbach, Jr., Natalie Leggett, Marcia Dickstein, Greg Huckins, Irina Voloshina, Trey Henry, Steve Erdody, Roberto Cani, Josefina Vergara, Songa Lee‐Kitto, Eun Mee Ahn, Christian Kollgaard, Alan Kaplan, Bruce Dukov, Darrin McCann, Phillip Levy, Jacqueline Brand, Shawn Mann, Rose Corrigan, Roger Wilkie, Sarah Thornblade, Wade Culbreath, Vanessa Freebairn–Smith, Jon Lewis, Andrew Duckles, Neel Hammond, Alyssa Park, Mike Valerio, Steve Holtman, Jeff Babko, Caroline Buckman, Mark Robertson, Shalini Vijayan, Andrew Bain, Minyoung Chang, Robert Brophy, Nico Abondolo, Brian R. Kilgore, Marisa Kuney, Alma Fernandez, Alex Iles, Serena McKinney, David Walther, Carolyn Riley, Rafael Rishik, Joseph Pereira, Maya Magub, Robert Schaer, Tereza Stanislav, Benjamin Jacobson, Andrew Bulbrook, Jonathan Moerschel, Eric Byers, Maia Jasper, Luke Maurer, Anthony Baldino, Doug Tornquist, Tamara Hatwan, Lara Wickes, Kevin Kumar, Teag Reaves, Laura Brenes, Jacob Braun, Dylan Hart, Jessica Guideri, Luanne Homzy, Helen Nightengale, Charlie Tyler, Steve Dress, Nathan Matthew David, Geoff Osika, Damian Montano, Ross Gasworth, Gary Hickman, Jenni Olson, Zach Dellinger, Thomas Harte, Joshua Ranz, Stephanie Matthews, Stefan Smith, Phillip Keen, Meredith Crawford, Geraldine Rotella, Evgeny Tonkha, Edward Meares, Benjamin Lash, Michelle Rearick, Chris Stoutenborough, Eric Shetzen, Kaylet Torrez, Mike McCoy, Claire Brazeau Bratt, Edward Atkatz, Chris Lane, Steve Suminski, Ryan Darke, Aaron Oltman, Morgan O'Shaughnessey, Phillip Triggs, Sooah Kim ont participé à l'enregistrement de Betrayal.