The seventh scale degree of a diatonic scale
In music theory, the term "leading tone" designates the seventh degree of a diatonic scale, frequently denoted by the Roman numeral "VII" during the analysis of harmonic progressions. The leading tone occupies a pivotal role in the world of music, contributing significantly to the overall harmonic and melodic character of a composition. As exemplified:
- In the key of C major, the leading tone is B.
- In the key of G major, the leading tone is F♯.
The leading tone earns its name due to its robust inclination to lead or resolve towards the tonic note, which is the first degree of the scale. In Western classical music, this resolution is deemed of utmost importance and contributes substantially to the sensation of closure and finality within a musical phrase or cadence.
The leading tone stands as an integral component of the dominant chord (V) within a diatonic scale. In the context of a major key, the dominant chord frequently incorporates the leading tone, instigating a profound sense of tension that ardently seeks resolution towards the tonic chord (I).
For instance, in the key of C major:
- The dominant chord (G major) encompasses the leading tone (B).
- This B possesses a formidable inclination to resolve upward to C, engendering a gratifying and conclusive resolution.
In minor keys, the seventh degree of the scale may be elevated (raised seventh degree or leading tone) to amplify its pull towards the tonic. This practice is especially prevalent in harmonic minor scales.
The leading tone further plays an instrumental role in cultivating melodic tension and molding musical phrases. Composers frequently employ the leading tone within melodies to foster anticipation and drama, thus making it an indispensable tool for conveying emotion and musical expression.