USAB meaning in Governmental ?

The United States Army Band, also known as "Pershing's Own", is the premier musical organization of the United States Army, founded in 1922. Before 2002, the United States Army Band was the only Washington-based military band to have participated in a theater of foreign combat operations. There are currently nine official performing ensembles in the unit: The U.S. Army Concert Band, The U.S. Army Ceremonial Band, The U.S. Army Chorus, The U.S. Army Blues, The U.S. Army Band Downrange, The U.S. Army Herald Trumpets, The U.S. Army Strings, The U.S. Army Voices, and The U.S. Army Brass Quintet.