A tremolo mechanism having a novel roller mounted beneath a tensioned string of a stringed musical instrument is described. During oscillatory movement, the tensioned string exerts both a static and a vibratory force on the roller. The roller rotates in relation to the tensioned string such that the static force is generally greater than any component of the vibratory force. The novel roller may be a saddle roller with a saddle block having two opposing block walls which form a roller cavity. The block walls each have a roller bore aligned along a roller axis. The saddle roller includes a cylindrical body attached to a roller pin and a circumferential seat receiving a tension string. The roller pin is rotatably disposed such that the saddle roller is in the saddle block cavity. The roller axis extends obliquely to define an oblique roller angle.