An exhaustive study of theater music would fill volume after volume with printed text and shelf after shelf with audio recordings. It would span the entire chronology of music history -- from the ancient Greeks to the 21st-century "virtual" theater. It would encompass every documented musical style from Monteverdi to Mancini and Handel to Hamlisch. It would be an overwhelming task to attempt such a study.
With that in mind, I need to set some parameters for this presentation. I need to narrow our focus to a smaller perspective -- one that will afford us a glimpse of the magnitude and diversity of this "ultimate art form" but at the same time allow us to view it as an artistic "whole," with the various forms and styles being contributors to the larger medium.
The forms implied by the phrase "theater music" are numerous, but for our purposes here, we will include only those that are "staged." By that, I mean works that are to be produced in a completely theatrical environment, incorporating the conventions of the theater -- set, costumes, lights, a script, acting (using some form of vocalization), movement, etc. This would include opera, singspiel, operetta, musicals, and the variations of those. It does not, for our purposes here, include incidental music for plays (or motion pictures), oratorio, or ballet.
The purpose of this endeavor is basically fourfold: 1) to examine the aspects that make theater music a valuable medium of expression; 2) to dispel a few of the common misconceptions about the art form; 3) to explore some diversities and artistic freedoms within the medium; and 4) to compare and contrast styles and techniques commonly found in the various forms of the medium.
It is not my intention to make this a survey of composers and compositions or to trace a chronology and developmental history of the art form. I hope it will serve as a significant introduction to the world of theater music, for those unacquainted with it, and give some fresh insight to those who have already grown to love the medium as I do.