Before World War II, most college bands were military-style and exclusively male. When the war began, most band members left to serve in the armed forces, which greatly strained the fraternity—to the point that 90 percent of chapters were forced to suspend activities. The Grand Council granted those chapters that were forced to suspend their activities "war furlough" so that instead of treating the chapter as inactive, their service would be honored. War furlough enabled a chapter to seal its records and keep its materials in safekeeping for the duration of the war. Petitions for war furlough required the signatures of all active members, the director of bands or other faculty member who was an honorary member of the fraternity, as well as the signature of the college or university president. Only five chapters remained active during the war: the Alpha chapter at Oklahoma A&M College, Alpha Beta at Butler University, Alpha Iota at the University of Colorado at Boulder, Alpha Omicron at Texas Technological College, and Alpha Pi at the University of Tulsa. With so many members serving overseas, including members of the Grand Council, the 1943 and 1945 national conventions were canceled.