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 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.
Johann Sebastian Bach and Richard Strauss, for instance, may both write passages that can be analysed according to the progression I-ii-V-I, despite vast differences in style and context.
Such harmonic conventions can be distilled into the familiar chord progressions with which musicians analyse and compose tonal music.
Various popular idioms of the twentieth century differ from the standardized chord progressions of the common-practice period.
Rhythmically, common practice metric structures generally include:[2] Durational patterns typically include:[3] Patterns of pitch and duration are of primary importance in common practice melody, while tone quality is of secondary importance.