Question: What melody from the French opera "Geneviève de Brabant" is used by Western Illinois University before all of it's football games and the United States Marine Corps as it's military hymn?

The "Marines' Hymn" is the official hymn of the United States Marine Corps, introduced by the first Director of USMC Band, Francesco Maria Scala.  It is the oldest official song in the United States Armed Forces.  The "Marines' Hymn" is typically sung at the position of attention as a gesture of respect.  Western Illinois University uses the hymn prior to all football games.  However, the third verse is also used as a toast during formal events, such as the birthday ball and other ceremonies.  They are the only non-military academy allowed to use the hymn.  The university has had permission to use the official nickname, mascot, and hymn of the Corps since 1927. <SEP> Francesco Maria Scala (1819 – 18 April 1903) also known as Francis M. Scala, was an Italian-born naturalized American military band director and musician.  It is thought that under his direction the USMC Band executed for the first time the melody "Potpourri-Fantasie" from the opera Geneviève de Brabant by Jacques Offenbach.  He was the first and one of the most important and influential directors of United States Marine Corps (USMC) Band.  He defined the instrumental organization that the band maintains, he was an extremely prolific musician and composer, and improved and enlarged the repertoire of the ensemble.  This melody is now known as the Marines' Hymn. <SEP> Whittington is an opera (described in the premiere programme as 'A New Grand Opera Bouffe Feerie, in Four Acts and Nine Tableaux) with music by Jacques Offenbach, based on the legend of "Dick Whittington and His Cat".  It was premiered in a spectacular production at the Alhambra Theatre, London, on 26 December 1874.  "Whittington" is the only major work of Offenbach to have received its premiere in London, and came between the incidental music for "La Haine" and his third version of "Geneviève de Brabant". <SEP> 3d Light Antiaircraft Missile Battalion (3d LAAM Bn) was a United States Marine Corps air defense unit equipped with the medium range surface-to-air MIM-23 HAWK Missile System.  During World War II, the battalion was known as the 3rd Defense Battalion and took part in combat operations at Pearl Harbor, Midway, Guadalcanal and Bougainville.  The unit was deactivated in late 1944 but was brought back into service as the Marine Corps began to transition to surface to air missiles for their air defense needs in the early 1950s.  During the mid to late 1950s, the battalion was based at Marine Corps Training Center 29 Palms, California and was one of two Marine Corps units that operated the land-based version of the RIM-2 Terrier Missile.  In January 1963 3d LAAM battalion was moved to Marine Corps Air Station Cherry Point, North Carolina and would eventually fall under the command of Marine Air Control Group 28 (MACG-28) and the 2nd Marine Aircraft Wing (2nd MAW).  3d LAAM Battalion's final combat tour saw it providing air defense for the Marine Corps area of operations during Operation Desert Shield/Desert Storm.  3d LAAM Battalion was deactivated on 30 September 1994 as part of the post-Cold War draw down of forces and because the Marine Corps had made the decision to divest itself of its medium-range air defense.