No, these guys have definitely seen the 1991 movie ‘Deadlock’ starring Rutger Hauer. And yes, male choral singing is present.
Video probably 2014-2016, Syria.
Terrorists burned a hostage alive
ISIS execution. Terrorists execute a Kurd
Explosion consequences. Terrorist act in Israel
ISIS terrorists demonstrate car bombings
Explosion at Kabul airport
ISIS boy cuts the throat of a man
ISIS terrorists crushed a captive with a tank
Execution of Egyptian militias
ISIS terrorist ambush