Composer, arranger, and orchestrator – what is the difference?
A composer is someone who creates original music. This could range anywhere from simply making up a melody to creating a fully realized orchestral work.
An arranger is someone who takes a piece of music that already exists, written by someone else, and “arranges” it, that is, re-works it, changes it. This might mean changing the instruments that play the piece, or adding harmony – for example, taking a piece for guitar and solo voice and re-working it for a large choir and piano. An arranger might also change the accompaniments and the rhythms of a piece – turning a slow number into a jazzy up tempo piece, or vice versa. An arrangement may be very simple or very complex, but as long as you still recognize the original material for what it is, it’s still considered an arrangement.
A composer may do any and all of that sort of arranging work with his/her own piece, as part of the composition of the work, and it not be considered an arrangement, unless it exists in separate versions. But even then, as the original composer did the arranging it’s not generally called an “arrangement”. Now, a composer might take a piece of music by another composer and re-work it to the extent that it is no longer considered an arrangement, but a new composition – for example, variations of a theme by whomever, or a work that quotes another pre-existing work.
An orchestrator is someone who takes a piece of music that is not originally for “orchestra” (or whatever medium-to-large instrumental ensemble – for the purpose of this discussion it need not actually be an orchestra) and creates a version for orchestra, deciding which instruments will be play and what notes, rhythms, etc, they actually play. Or, an orchestrator might do a new orchestration for some music that has already been orchestrated. An orchestrator may, as part of an orchestration, do some “arranging” work – adding harmonies, creating new accompaniments, etc. In such cases, that work may be considered simply part of orchestrating the piece, or the work may be considered “arranged and orchestrated by” this person.
I personally feel that orchestration is a type of arrangement. It’s a re-working of the original piece, an “arrangement” for orchestra. But you generally won’t hear an orchestration being referred to as an arrangement unless it includes significant changes in the harmonies &/or rhythms &/or accompaniments.
In the (legit) classical music world it’s not so common to find orchestrators. You do find arrangements, but, typically, classical works for orchestra were orchestrated by the composer as part of the process of composition. You will, by necessity, have orchestrators in the more commercial sort of “classical” music – background music, “light” classics, possibly pops concerts...anything that has the feel of “The Three Tenors” doing music that a general audience will actually recognize (i.e., not opera or other music originally for a big solo voice and big orchestra), someone had to do those orchestrations.
In the contemporary popular music world (of whatever genre), you don’t generally find orchestrators or arrangers because most of that sort of work ends up being considered part of writing the music and is typically credited that way (either “music by whomever, if lyrics are credited separately, or simply “by whomever”, often a list of several contributors). It seems that the place you’ll most likely find orchestrators separately credited is in musical theatre. New orchestrations and arrangements are often written for Broadway revivals. And, while a theatre composer may do his/her own “arranging”, it’s much more common that there is a separate orchestrator.
