According to the generally accepted standards the classical period in music lasts from 1750 to 1820. It is the second half of the eighteenth century and up to the half of the nineteenth. During almost one hundred years a lot of technological advances and discoveries were made in different countries throughout Europe, North America and the whole world later. The technology was developing so rapidly that it influenced not only the working class but all the strata of society. This period in the world history is called Industrial Revolution.
The notion of Industrial Revolution is closely related to innovations but they were made in particular fields. First of all, it is fabric manufacturing. The first automatic machines were designed especially for cotton spinning. English Luddites opposed against such changes and destroyed cotton mills and other advances. Nevertheless, the technology made its progress. Secondly, it was the improvement in the iron making industry, which allowed creating more precise instruments. Thirdly, there were innovations in the usage of steam. James Watt introduced his steam engine and this discovery changed the world completely because it speeded up the development of automobile and train.
On the other hand, such innovations and mass transfer of knowledge allowed middle class to raise and understand its political meaning. For example, the classical period coincides with the French revolution.
As for the music, the classical period is one of the most productive in the musical history. Such changes in productivity are closely related to the rise of the middle class. From the economic point of view, the rich bourgeois created the patronage system to support composers and musicians (Classical period). The style of music also was changed because the middle class was less educated and needed music, which was easy to understand. Opera buffa developed as a genre at that time. Besides, to return thanks to their patrons a gallant music appeared.
Classical period, n.d. Retrieved from http://www.u.arizona.edu/~douglast/Pages/The%20Classical%20Period.html