U.S. Army Reserve 78th Army Band Jazz Combo performs during the Meet Your Army Week event in the Boston Commons, in Boston, Massachusetts, April 13. The U.S. Army offers 150 career choices. Army musicians perform in a variety of ensembles ranging from ceremonial band to jazz band to small ensembles, playing all styles of music. They are primarily responsible for performing and rehearsing as a professional musician within different ensembles of an Army band.