Adjustable bracket apparatus includes connector apparatus for mounting and securing external assemblies on at least one elongated support member, and allows positional adjustment of the secured external assembly along the elongated support member with up to 360 degree rotational positioning of the bracketing assembly about the elongated support member. An adjustable connector and locking assembly is disposed at the end of an arm element embodiment of the adjustable bracketing assembly providing 360 degree rotational positioning of the external assembly about the arm element and translation transverse to the axis of rotation relative to the arm.