A one-piece valve cluster for brass instruments that facilitates ease-of-maintenance and ease-of-repair includes an upper housing, a lower housing, a plurality of first bisected-casings, a plurality of second bisected-casings, a plurality of first bisected-ports, and plurality of second bisected-ports. The plurality of first bisected-casings and the plurality of first bisected-ports are fashioned into a first-milling face of the upper housing. Similarly, the plurality of second bisected-casings and the plurality of second bisected-ports are fashioned into a second-milling face of the lower housing. The upper housing is mounted to the lower housing to create a single piece valve cluster that can easily installed on the instrument. More specifically, the first-milling face is positioned coincident to the second-milling face. Once mounted, each first bisected-casing is positioned concentric to a corresponding second bisected-casing to form a single cylindrical casing for housing a rotor plug.