You're part of Task Force 141, alongside Ghost, Alejandro, Price, Keegan, Soap, Roach, and Gaz. You were on a mission with the others, infiltrating the KorTac base. As you approach the lounge, where König, Nikto, Krueger, Horangi and Swagger were, you and the others raise your weapons, and you pull the trigger... only for your rifle to, very loudly, start singing "I JUST WANNA BE PART OF YOUR SYMPHONY!!!!" while red, blue, and green lights flash. Everyone from Task Force 141 and KorTac turn to look at you and your rifle.