n.
an equestrian drill performed by the Royal Canadian Mounted Police (see Image 1).
Type: 4. Culturally Significant — Musical rides evolved from cavalry drills designed to prepare riders and mounts for the battlefield. Early musical rides were performed by the Royal Canadian Dragoons, for example (see the 1887 quote). The predecessor of the RCMP, the North West Mounted Police, developed a musical ride that was first performed on 16 Jan. 1887 before Commissioner Lawrence Herchmer and his wife in Regina, SK, and consisted of 32 riders. The force began performing the ride in public in 1901 (see RCMP Veterans' reference). Today, the term is now almost exclusively connected with the Royal Canadian Mounted Police. The RCMP musical ride has become a national symbol (see the 1970 and 2006 quotations). See Chart 1 on the frequency of the term in Canada.
See also OED-3, s.v. "musical".
See also: Mountie Royal Canadian Mounted Police
Images:

Image 1: Musical ride, North Vancouver, 2013. Source: Wikimedia Commons. Photo: Shaundd
Chart 1: Internet Domain Search, 16 Aug. 2012