The main kinds of instrumental music were the sonata, trio, string quartet, quintet, symphony (performed by an orchestra) and the solo concerto, which featured a virtuoso solo performer playing a solo work for violin, piano, flute, or another instrument, accompanied by an orchestra.

Instrumental music was considered important by Classical period composers. Unlike the harpsichord, which plucks strings with quills, pianos strike the strings with leather-covered hammers when the keys are pressed, which enables the performer to play louder or softer (hence the original name 'fortepiano,' literally 'loud soft') and play with more expression in contrast, the force with which a performer plays the harpsichord keys does not change the sound. The harpsichord was replaced as the main keyboard instrument by the piano (or fortepiano). Variety and contrast within a piece became more pronounced than before and the orchestra increased in size, range, and power. It also makes use of style galant which emphasized light elegance in place of the Baroque's dignified seriousness and impressive grandeur. It is mainly homophonic, using a clear melody line over a subordinate chordal accompaniment, but counterpoint was by no means forgotten, especially in liturgical vocal music and, later in the period, secular instrumental music.

Classical music has a lighter, clearer texture than Baroque music, but a more varying use of musical form, which is, in simpler terms, the rhythm and organization of any given piece of music. The Classical period falls between the Baroque and the Romantic periods. The Classical period was an era of classical music between roughly 17.

Classical romantic moods