Britten used the different families of the orchestra to define the structure of the young person's guide to the orchestra

That statement is true

. It was intentionally created as a comission for the British educational documentary film called Instruments of the Orchestra that is directed by Muir Mathieson. He used  different families of the orchestra to define the structure, , generally moving through each family from high to low

when the united states took over

answer; form new memories;