Today, it is estimated that there are more Ludwig Standard Symphonic Series Timpani in use throughout the world than all other models and brands combined. The Ludwig Standard Timpani kettles are mounted directly to the struts of the drum. This differs from the Professional and Grand Symphonic series timpani. Ludwig's patented Balanced Action Pedal allows for tuning of a major sixth per each drum. The Standard Series are built with interior tuning mechanics and are available in smooth copper or fiberglass kettles.