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, even before Roman times, bugles, drums, and other loud musical instruments were used for clear communication in the noise and confusion of a battlefield.
During World War I bugles were used by Canadian and Commonwealth troops. They are generally associated with ‘’Reveille’’ or ‘’Rouse’’ (wake up call) and ‘’Retreat’’ or ‘’Lights Out’’. They were sometimes crucial to indicate an alert for possible attack.