The military occupational specialty (MOS) 420C is for Warrant Officer Bandmasters in the U.S. Army. These officers are responsible for the unit-level command and control of their bands.
Their responsibilities include:
Uniform Code of Military Justice authority
Administration
Operations
Training
Supply
Warrant Officer Bandmasters also:
Serve as the OIC or commander of band personnel
Account for property and equipment
Establish policies and procedures
Advise senior commanders on how to employ the band’s music support teams
Warrant Officers also command aircraft, maritime vessels, special units, and task organized operational elements. They provide advice, counsel, and solutions to support their unit or organization.