The Classical Era was the approximately seven decades from about 1750 to 1820, which followed the Baroque Era (about 1600 to 1750) and preceded the Romantic Era (from around 1830 and into the early 20th century).
Music of the Classical Era differed from Baroque music in numerous ways. This was largely the result of technological advances accompanying the Industrial Revolution, particularly in metallurgy and manufacturing techniques, that allowed the development of more powerful and more stable instruments. For example, the development of cast iron frames for pianos allowed greater tension in the strings, thus enabling increased chromatic and dynamic ranges. Enhancements to woodwind instruments included the development of axle-mounted keys, which made them more ergonomic and easier to play, increased key durability and allowed greater accuracy of tone hole placement, thereby improving consistency of intonation. The addition of valves to brass instruments expanded their chromatic range (i.e., filling in 'missing notes') and their ability to play in different keys.
Other differences from the Baroque period included the use of distinct melodic lines along with a greater variety of melodies, rhythms, dynamics and keys within individual pieces. Also, textures became lighter and clearer and had less complexity. Orchestras increased in size, range and power, new instruments were introduced, most notably the clarinet, and the piano replaced the harpsichord as the main keyboard instrument.
The development and subsequent refinement of the piano was a major factor in the development of Classical Era music. It's range expanded from about five octaves to 6.5 octaves and its dynamic range increased substantially as compared with the harpsichord and the pianoforte. This enabled composers to write music with more subtle dynamics and articulation and it also made the piano much more suitable for both solo performances and for use as part of an orchestra.
Among the best-known composers of the Classical period were Haydn (1732-1809), Mozart (1756-1791), Beethoven (1770-1827) (his earlier works), Franz Schubert (1797-1828), Muzio Clementi (1752-1832) and Christoph Gluck (1714-1787).