A sliding mount for removable insertion of a module into a body of an instrument having longitudinal strings, the body defining a transverse cavity extending from a lateral edge. The sliding mount includes a blade for fixation to the module by a generally planar face generally parallel to and spaced apart from a plane the strings define. The blade has first and second edges oriented perpendicularly to the lateral edge when inserted into the body. A sheath for fixation to the body by a generally planar face is configured to receive the blade. The sheath has a first and second lip configured to define opposing channels the edges that slidingly engage upon insertion of the blade into the sheath.