Premise: The Tony Award for Best Direction of a Play has been given since 1960. Before 1960 there was only one award for both play direction and musical direction, then in 1960 the award was split into two categories: "Dramatic" and "Musical". In 1976 the Dramatic category was renamed to Play. For pre-1960 direction awards please reference Tony Award for Best Director.
Hypothesis: The one award for both play direction and musical direction was split into multiple categories.