There probably would have been orchestras of some sort ever since musical instruments were invented, with a group of musicians playing together. However the roots of the symphony orchestra as we know it can be traced back to the 17th century.
In the early 17th century there existed small groups of musicians that played a random assortment of instruments. However, the organization of these groups varied.
It was only when Montverdi established the opera genre in Italy that a standard was first set for a group of musicians playing together. Monteverdi ensured that the singers had a body of accompanying instruments, most of which were viols, predecessors of today’s stringed instruments.
The importance of string groups was increased when Lully, court composer to Louis XIV of France, established a string orchestra called the ‘24 Royal String Players.’ String groups formed following that had a maximum of some 25 players, but a smaller group was the norm as most composers usually wrote for strings or woodwind and a single keyboard instrument.
Towards the latter part of the 17th and early 18th centuries, Italian violinists-composers such as Correli, Torelli, Tartini and Vivaldi established the concerto grosso and the solo string concerto, and the development of these greatly bolstered the importance of string orchestras.
The early composers wrote simple pieces, placing emphasis on treble and bass lines. The first and second violins played in unison a third apart, and the violas (and often the double bass) doubled the cello part. Other instruments like recorders, horns or timpani, were added as required by each composer, sometimes as soloists, or to provide special effects. There was also a harpsichord continuo, which 'continually' filled in the harmony, reinforced by a single cello, the basso continuo.
Picture: Typified late 17th- and early 18th- century orchestra
Compared to the early part of the 17th century, the orchestral sounds were definitely fuller and richer. The size of the orchestra grew to about 35 members, however this still varied widely in different areas. It was during this period that instrumental music grew in stature to match that of vocal music.
