Elastic scoring
Elastic scoring is a style of orchestration or music arrangement that uses interchangeable parts, allowing for various groups of instrumentalists or vocalists to perform a piece of music. This style was first used by the Australian composer Percy Grainger. The South African composer Michael Blake also used it for some of his works.
Purpose
An example of this technique of orchestration is when a composer or arranger provides extra sheet music parts so a flute quartet can play the same piece as a group comprising two flutes, alto flute and bass flute, resulting a choir-like sound. In other words, a subtle re-engineering of the original work.This technique involves making extra and/or interchangeable musical parts which provide substitutions for more or fewer musicians depending on what is required for an individual performance. This also allows a musical work to be played in smaller communities where the required instruments may not always be available.
One of the main tenets of elastic scoring is that the new arrangement preserve as much as possible the original interval relationship between notes while not being overly concerned with timbre or number of instruments. Timbre is the aspect of music varied most through changing instrument or number of instruments.