Abstract: Described is a twin valve attachment for musical instruments, such as a trombone. The attachment includes a lever that is rotatable between a B-Flat configuration and an F note configuration. Also included are first and second rotary valves. The first rotary valve is operably connected with the F lever, while the second rotary valve is operably connected with the first rotary valve. F-attachment piping is fluidly connected with both the first and second rotary valves. Thus, a user may rotate the F lever to selectively direct air flow through the F-attachment piping (for the F note configuration) or bypass the F-attachment piping (for the B-Flat configuration).