Common practice period

In Western classical music, the common practice period was the period of about 250 years during which the tonal system was regarded as the only basis for composition. It began when composers' use of the tonal system had clearly superseded earlier systems and ended when some composers began using significantly modified versions of the tonal system and developing other systems as well. Most features of the common practice (the accepted concepts of composition during this time) persisted from the mid-Baroque period through the Classical and Romantic periods, roughly from 1650 to 1900.

There was much stylistic evolution during these centuries, with patterns and conventions flourishing and then declining, such as the sonata form. The most prominent unifying feature throughout the period is a harmonic language to which music theorists can today apply Roman numeral chord analysis; however, the "common" in common practice period does not directly refer to any type of harmony, rather it refers to the fact that for over two hundred years only one system was used.

Technical features

Harmony

The harmonic language of this period is known as "common-practice tonality", or sometimes the "tonal system" (though whether tonality implies common-practice idioms is a question of debate). Common-practice tonality represents a union between harmonic function and counterpoint. In other words, individual melodic lines, when taken together, express harmonic unity and goal-oriented progression. In tonal music, each tone in the diatonic scale functions according to its relationship to the tonic (the fundamental pitch of the scale). While diatonicism forms the basis for the tonal system, the system can withstand considerable chromatic alteration without losing its tonal identity.