dominant(V) belongs to the tone and chord.

"Attributive" refers to the fifth level of the main key.

The function of dominant chords is reflected in the cadence. In a major key, a cadence is formed from the most unstable dominant chord in the key to the most stable main chord, which can release the tension accumulated in the harmonic progression and give the phrase a sense of termination.

The dominant seventh chord has a strong directivity to the main chord, because its component sounds contain two leading tones, and these two leading tones can each be resolved to the main chord through semitones. The seventh tone 4 of the dominant seventh chord resolves downward to the third tone 3 of the tonic chord, and the third tone 7 resolves upward to the root note 1 of the tonic chord. The dissonant tritone either contracts into a harmonious major third or expands into a minor sixth, resolving the tension of the dominant chord. The root note 5 of the dominant chord remains the fifth of the dominant chord.