At the most basic level, the producer provides the funding to find suitable projects; commission scores and librettos; engage casts; hire set designers, music directors, orchestrators, lighting designers, choreographers; schedule rehearsals and out-of-town tryouts; reserve theatres on Broadway; and in general promote shows and sell tickets.

Ken Davenport: Producing 101--The Three Fundamentals of Producing Theater

Ken Davenport’s Book

However, major producers were much more than facilitators and contracting agents.  For better or for worse, they had minds of their own.  They could dictate their own concepts of good taste in music and language; they could demand additions to or cuts from a score.  They could make or break reputations; they could be angels or devils (sometimes on the same show); they could cling to the past or foresee the future.  They could help start revolutions or try to prevent them from occurring.  

They were impresarios in the best or worst sense of the word.  The good ones were as much a part of the development of the American Musical Theatre as the composers, lyricists, writers, orchestrators and musical directors.  They backed the people who would create new sights and sounds; they took the losses when the vision didn’t work on the stage.  The lesser lights tended to have their day in the spotlight and then fade from sight.

We are going to concentrate on the more influential impresarios of their era.  It will be interesting to see how they started their careers and how their careers developed (or not).  Almost all had some initial interest in show business.  Some started with a company of performers and musicians; they produced shows to provide salaries for the company personnel.  Some owned real estate (theatres); they produced shows so that their theatres would be booked throughout a year.

But slowly, as you will see, the good producers backed the best composers and pushed the musical forward from entertainment to art.