In 1946, Britten was asked to write the music for an educational film called The Instruments of the Orchestra. He chose a hornpipe dance by Henry Purcell (1659-1695) from the incidental music to Abdelazer or the Moor's Revenge, a play by 17th-century playwright Aphra Behn. Britten conceived the variations on this melody in such a way that each would highlight a different instrument or instrumental group in the orchestra. Even the theme is divided into six sections featuring, in turn, the entire orchestra, the woodwinds, the brass, the strings, the percussion, and the full orchestra again.
In the variations themselves, which are thirteen in number, Britten matched instrumental colour with musical character, producing short vignettes that run the gamut from playful to serious. The woodwinds are introduced in the order in which they are written in the score: flute, oboe, clarinet, bassoon. Then we hear the violins in a Brillante – alla polacca variation, the violas and the cellos in two wistful slow melodies, and the basses in a humorous variation that sometimes sounds like a waltz and sometimes doesn't. Britten didn't forget (and didn't want his %u201Cyoung person” to forget, either) that the family of string instruments included the harp, which is treated to a goodly number of arpeggios and cascades of chords following the double-bass variation.
The brass instruments are next: the festive signals of the horns and the lively game of the trumpets are followed by an Allegro pomposo for three trombones and tuba. Finally, an ingenious variation featuring the timpani and percussion reduces the Purcell melody to a rhythmic skeleton, with the strings providing a rudimentary harmonic accompaniment.
The piece is crowned by a brilliant fugue begun by the piccolo; the other instruments enter one by one in the same order in which they have been introduced in the course of the variations. At the end, the fugue theme is combined with the original form of the Purcell melody, which is played by the brass as the other instruments carry on their florid contrapuntal parts. The work concludes with an exuberance that, in the words of Imogen Holst, %u201Cis surely one of the ingredients that makes Britten's music acceptable to so many inexperienced listeners, whatever their ages may be.”