The orchestra has expanded over time. In the present day, a typical symphony orchestra consists of woodwinds, brass, percussion and strings. Other instruments such as the piano, harp and celeste may be occasionally added depending on the repertoire.
The first orchestras were made up of small groups of musicians who joined forces for civic and celebratory events. In the 11th century, the various families of instruments started to evolve, for instance the string family, which by this stage consisted of the ancestors of the modern violin, viola, cello and double bass. In Italy in the 16th century, noble families employed musicians for entertaining guests at the court. In the 17th century, opera was born, incorporating orchestral and vocal collaboration, which spread quickly throughout Europe. The orchestra became somewhat standardised in the classical period, under the influence of Joseph Haydn, who composed 106 symphonies and subsequently the innovative Ludwig van Beethoven.