Common tone (chord) in the context of "Pitch class"

A riff is a short, repeated motif or figure in the melody or accompaniment of a musical composition. Riffs are most often found in various genres of rock music (including punk and heavy metal music), as well as Latin, funk, and jazz, although classical music is also sometimes based on a riff, as in Ravel's Boléro. Riffs can be as simple as a tenor saxophone honking a simple, catchy rhythmic figure, or as complex as the riff-based variations in the head arrangements played by the Count Basie Orchestra.

David Brackett (1999) defines riffs as "short melodic phrases", while Richard Middleton (1999) defines them as "short rhythmic, melodic, or harmonic figures repeated to form a structural framework". Author Rikky Rooksby states: "A riff is a short, repeated, memorable musical phrase, often pitched low on the guitar, which focuses much of the energy and excitement of a rock song."

Voice leading (or part writing) is the linear progression of individual melodic lines (voices or parts) and their interaction with one another to create harmonies, typically in accordance with the principles of common-practice harmony and counterpoint. These principles include voices sounding smooth and independent, generally minimising movement to common tones as well as steps to the closest chord tone possible, therefore minimising leaps where possible. As a result, different voicings and inversions of chords may provide smoother voice leading.

Rigorous concern for voice leading is of greatest importance in common-practice music, although jazz and pop music also demonstrate attention to voice leading to varying degrees.