During Bach's time, orchestras were typically small, consisting of about 20-30 musicians. These ensembles were often assembled for specific occasions, such as performances of operas or church music, and the instrumentation could vary depending on the venue and the available resources.
The core of the orchestra was typically made up of string instruments, including violins, violas, cellos, and contrabasses (double basses). Woodwinds and brass instruments were often added to provide color and variety. Common woodwinds included flutes, oboes, and bassoons, while brass instruments included trumpets, horns, and trombones.
In Bach's time, orchestral instruments were not standardized as they are today. For example, there were many different types of flutes and oboes, each with its own unique tuning and characteristics. This meant that musicians had to be versatile and adaptable, and they had to make adjustments to their playing depending on the instruments they were given.
Despite the limitations of the time, Bach was a master of orchestral composition. His works for orchestra are characterized by their rich textures, skillful counterpoint, and expressive use of instrumentation. Some of his most famous orchestral works include the Brandenburg Concertos, the Orchestral Suites, and the Sinfonias from his cantatas.
Bach's music had a profound influence on later composers, and his innovations in orchestral writing helped to shape the development of the modern orchestra.