- Historians say that the first signs of the formation of a symphony orchestra were in ancient Egypt. By the eleventh century, musicians assembled in instrument families. In the latter half of the sixteenth century, composers began writing music for orchestras. However, the instruments were not the same as those used today. In the seventeenth century, composers emphasized the string instruments in their compositions, which prompted the string section to become the core of the symphony orchestra. In the eighteenth century, a typical symphony orchestra contained flutes, horns, oboes, trumpets, clarinets, violins, bassoons, cellos, violas, basses and timpani.
- At bare minimum, a full symphony orchestra has 30 members, but typical contemporary orchestras have closer to 90 musicians. Within the orchestra, there are instrument families. For the string family, there are two sections of violins as well as violas, basses and violoncellos. In the woodwind family, there are flutes, piccolo, oboes, English horns, bassoons and clarinets. The brass family consists of tuba, trombones, trumpets and horns. There is also the percussion family , comprised of timpani, snare drum and bass drum, and possibly the addition of a triangle, cymbals, glockenspiel, chimes or wood blocks.
- If the symphony orchestra is small, with about 20 to 30 musicians, it is called a chamber orchestra, and consists of violins, violas, double basses, cellos and brass or woodwind instruments. A smaller orchestra of under 15 musicians is known as a sinfonietta. Some larger symphony orchestras--sometimes called philharmonics--supplement the traditional instruments with other instruments or objects, such as a gong, bells or even toys.
- The genre of music determines the instruments in the symphony orchestra. For example, if the ensemble is performing baroque music dating from the seventeenth to early eighteenth centuries, the instruments may include a harpsichord and pipe organ. If the orchestra is playing music of the Romantic era from the nineteenth century, there may be harpists or even a wind machine. Orchestras playing twentieth century compositions may have an electric guitar, synthesizer or theremin in their midst.
- Throughout the eras, the size and composition of a symphony orchestra has evolved. In the early eighteenth century, a typical ensemble was comprised of 20 members but, by the end of that century, the symphony orchestra had expanded to 40 musicians. A half century later, the ensemble had grown again to have 60 players. Contemporary symphony orchestras consists of 90 members, though some compositions may demand an ensemble of over 100 musicians.
