The Orchestrator

The word orchestrator sounds like it means conductor. It does not, and it does not mean composer either, and the difference between those three jobs turns out to map unusually well onto what is happening in software.

A composer creates the original material and decides what the music actually is. In this book’s terms, the composer is whoever decides what the system should do: the objective, the outcome, the requirement. A conductor shapes the performance in real time — tempo, dynamics, balance, entries, exits. In this book, the conductor is the runtime: the system managing real-time execution. An orchestrator, in the musical sense, is neither. Orchestration is the art of taking musical material and deciding which instruments play it, how they combine, and when each section enters. What has shifted in the last few years is which of these three jobs is up for automation. The conductor — the runtime — will probably be a system. The human role moves to orchestration: designing the ensemble, assigning the parts, setting the boundaries within which the performance happens. And sometimes, writing the melody too.