Guard Mount refers to two things. The first is the actual forming (mounting) of a military security group called: the Guard. The second is the bugle call which was used to signal the formation of the group.

Military formation

Guard mount refers to a pre-shift official formation among designated United States Air Force Security Forces members. This meeting is usually held after all security personnel have "armed up" or received their weapons and equipment for the shift. During the formation the flight

Flight (military unit)

A flight is a military unit in an air force, naval air service, or army air corps. It usually comprises three to six aircraft, with their aircrews and ground staff; or, in the case of a non-flying ground flight, no aircraft and a roughly equivalent number of support personnel. In most usages,...

 leader (known as the flight chief) will discuss topics such as current squadron, base or other air force level news, current terrorism warnings or military intelligence, and weapons, vehicle and ground safety. Members also will be inspected and assessed on their appearance, uniform and checked for required equipment. When held in a deployed combat threat environment, guardmount is somewhat akin to US Army Pre-combat Checks and Pre-combat Inspections, PCC and PCI respectively.

Bugle call

Guard Mount is a bugle call

Bugle call

A bugle call is a short tune, originating as a military signal announcing scheduled and certain non-scheduled events on a military installation, battlefield, or ship. Historically, bugles, drums, and other loud musical instruments were used for clear communication in the noise and confusion of a...

which sounds as a warning that the guard is about to be assembled for guard mount.