Benjamin Britten (1913-1976), an English composer, wrote the attractive Young Person's Guide to the Orchestra in 1946 as an introduction to the instruments of the orchestra. He used a theme by Henry Purcell, a great English composer of the seventeenth century. (A theme is a melody used as the basis for a musical composition.) The majestic theme is first presented by the full orchestra and then by each section of the orchestra in turn: woodwinds, brasses, strings, and percussion. Thirteen variations, or varied repetitions of the theme, are then heard. Each highlights a different instrument. Together, they vary in dynamics, speed, and tone color, as well as mood. The variations follow each other without pause and last from about 30 seconds to 1 minute. (Variation 13, however, which features many percussion instruments, lasts almost 2 minutes.) Woodwind, string, and brass instruments are generally presented from highest to lowest in range. Variation 13 is followed immediately by a concluding section beginning with a lively new tune played by an unaccompanied piccolo. Then other instruments enter, each playing the same tune. After woodwind, string, brass, and percussion instruments have had their turn, the brasses bring back the main theme and provide an exciting ending. Below is an interactive version of Britten's Young Person's Guide to the Orchestra.