Modulation (music)

Modulations articulate or create the structure or form of many pieces, as well as add interest.

Without it there is little music, for a piece derives its true beauty not from the large number of fixed modes which it embraces but rather from the subtle fabric of its modulation.The quasi-tonic is the tonic of the new key established by the modulation.

In analysis of a piece that uses this style of modulation, the common chord is labeled with its function in both the original and the destination keys, as it can be heard either way.

There are two main types of enharmonic modulations: dominant seventh/augmented sixth, and (fully) diminished seventh.

By combining the diminished seventh with a dominant seventh and/or augmented sixth, altering only one pivot note (by a half tone), it is possible to modulate quite smoothly from any key to any other in at most three chords, no matter how distant the starting and ending keys (be aware that only when modulating between key signatures featuring double-sharps/flats may the need to respell natural notes enharmonically arise); however, this may or may not require the use of altered chords (operating in the harmonic minor without an augmented sixth would not) where the effect can be less subtle than other modulations.

If also employing enharmonic respelling of the diminished seventh chord, such as that beginning the modulation in the above examples (allowing for three other possible diminished seventh chords in other keys), the versatility of this combination technique and the wide range of available options in key modulation become apparent.

This type of modulation is particularly common in Romantic music, in which chromaticism rose to prominence.

Other types of enharmonic modulation include the augmented triad (III+) and French sixth (Fr+6).

Despite the common chord (ii in C major or i in D minor), this modulation is chromatic due to this inflection.

The combination of chromatic modulation with enharmonic modulation in late Romantic music led to extremely complex progressions in the music of such composers as César Franck, in which two or three key shifts may occur in the space of a single bar, each phrase ends in a key harmonically remote from its beginning, and great dramatic tension is built while all sense of underlying tonality is temporarily in abeyance.

The sequential passage will begin in the home key, and may move either diatonically or chromatically.

Harmonic function is generally disregarded in a sequence, or, at least, it is far less important than the sequential motion.

The most common modulations are to closely related keys (I, V, IV, vi, iii, ii).

[24] Modulation to the dominant or the subdominant is relatively simple as they are adjacent steps on the circle of fifths.

Modulations to the relative major or minor are also simple, as these keys share all pitches in common.

Many musicians use the circle of fifths to find these keys and make similar charts to help with the modulation.

In many genres of music, moving from a lower key to a higher often indicates an increase in energy.

Change of key is not possible in the full chromatic or the twelve tone technique, as the modulatory space is completely filled; i.e., if every pitch is equal and ubiquitous there is nowhere else to go.

Example of modulation from the tonic to the dominant. [ 1 ] Play ⓘ
Key signature change example: C major to C minor.
Common-chord modulation in the opening of Chopin's Prelude in C minor , Op. 28, No. 20. [ 4 ] Play ⓘ
Common-chord modulation in Tchaikovsky 's Album pour enfants (1887), Op. 39, No. 10, Mazurka [ 5 ] Play ⓘ
Common-chord modulation in the opening of Mozart 's Sonata in D Major, K. 284 , III [ 6 ] Play ⓘ
Modulation from D major to D ♭ major in Schubert 's Op. 9, No. 14, D. 365, mm. 17–24, using the German sixth , in the new key, that is enharmonic to the dominant seventh in the old key. [ 8 ] Play ⓘ
Modulation from A minor to E ♭ minor in Schubert's Op.29, D. 804, I, mm.144-49, using vii o 7 : G ♯ o 7 ≡ D o 7 (≡ B o 7 ≡ F o 7 ) [ 9 ] Play ⓘ
Modulation between relative keys, C minor and E ♭ major, using a common tone, G, in Schubert's Op. 163 (D. 956). [ 11 ] Play ⓘ
Common-tone modulation between chromatic mediants in Mozart's K.475 [ 12 ] Play ⓘ
Chromatic modulation in Bach's Du grosser Schmerzensmann , BWV 300, mm. 5–6 [ 15 ] ( Play ⓘ with half cadence , Play ⓘ with PAC) transitions from F major to D minor through the inflection of C ♮ to C ♯ between the second and third chords. Note that there is no common chord.
Phrase modulation in Mozart's Sonata in A major, K.331, III ( Alla turca ), mm. 6–10. [ 16 ] Play ⓘ
Sequential modulation in Beethoven 's Sonata Op. 53 , movement I [ 18 ] Play ⓘ
Sequential modulation in Schubert 's Piano Sonata in E Major, D. 459 , movement III [ 18 ] Play ⓘ
Sequential modulation through the circle of fifths in Quartet Op. 3, No. 3, IV, Hob. III:15, [ 20 ] formerly attributed to Haydn (ca. 1840) Play ⓘ
The circle of fifths drawn within the chromatic circle as a dodecagram [ 22 ]
Modulation up a whole step at the end of " Because the Night " Play ⓘ