One of the earliest functions for a bugler (or actually someone playing an animal horn) was the call to worship. This call advises that services are about to start. This is done at a slower more relaxed pace then many of the other calls consistent with it's purpose of not only informing the listener but setting a mood.
Copyright www.ScoutBugle.com 2004-2009
Reference: Music and Bugling Merit Badge Book from the Boy Scouts of America