Grade Six Music Theory Composition; Lesson 3 - Cadences
Quick Revision of Cadences
If you took Grade Five music theory, you already know a lot about cadences. We will review them anyway, however! A cadence is a sequence of chords which concludes a musical phrase.
- The perfect cadence Va-Ia signifies a close. It’s usually found at the end of a piece or main section.
- The plagal cadence IVa-Ia also has a final effect, but is softer and less dramatic.
- An imperfect cadence, e.g. ii-V or vi-V, is often found at the end of an antecedent (questioning) phrase, or at the end of a middle section of the music. (Any cadence which ends on V is an imperfect cadence.)
- An interrupted cadence, e.g. V-vi, is quite a rare type of cadence. Interrupted cadences are so named, because instead of following chord V with chord I as is usually expected, V is followed by vi (in a major key) or VI (in a minor key). Other variations are possible, but chord vi/VI is the most common.
- An inverted cadence, e.g. Vb-Ia, can also occasionally be found at the end of the antecedent phrase or the end of a middle section. An inverted cadence is one where a chord is in first inversion instead of in root position.
Why do Cadences Matter in the Grade Six Music Theory Composition?
Although you are going to compose an unharmonised piece in the Grade Six music theory exam, it’s vital to realise that there should still be an implied harmonic structure to the melody.
This means that the notes you choose for the melody at the half-way point and at the end have to fit with the chords which would make up the cadences. If you choose notes which lie outside these chords, your cadences will not sound clear and you will lose points on structure.
Remember that “notes which fit” can include passing notes and other non-chord notes – you don’t have to stick to the notes from the triad, but the triad-notes should be prominent. For example, if the implied chord is C major, you could write this, because the D and the F would be passing notes, leaving C-E-G as the triad.
But if you wrote this
the implied chord would probably be D minor, although most of the actual notes are the same as in the first example. Why is this?
- Notes which fall on strong beats have prominence. In the second example, the F falls on the strong beat but is not part of a C major chord. (In duple and triple time, the strong beat is the first beat of the bar. In quadruple time there is a secondary strong beat half way through the bar.)
- Notes which fall on the beat have prominence. In the first example this is C-E-G. In the second it is F-G-D.
- Notes which are approached by a leap have prominence. In the second example, the D is approached by a larger interval than the other notes, but is not part of a C major chord.
- Notes which are repeated have prominence. The repetition of the F in the second example makes it stand out.
Your composition will most likely contain two cadences; an imperfect or interrupted cadence at the half-way point, and a perfect cadence at the end. If you choose the question in the Grade Six music theory exam which asks for a modulation at the end of the melody, your perfect cadence will be in the new key.
Examples
The following simple melodies illustrate how the notes chosen for the melody reflect the implied harmony. Our first example is from an Allegro moderato by Mozart (K.3 – written when he was six years old!)
- These twelve bars lead up to the end of the first section.
- The piece is in Bb major, and the first six bars of this extract are in Bb major, but the introduction of the E natural in bar 7 signifies that the music is modulating to F major – the dominant key.
- At the end of bar 5, the note A is a part of chord V in Bb major (F major), and the Bb in bar 6 is part of chord I.
- In bar 11, the G is a very prominent note because it falls on the strong beat and it is sounded three times. It is the dominant note of the dominant chord in F major (C major), and the section ends on a tonic F major chord in the new key.
- Both cadences are perfect.
Our next excerpt is from an Andante Grazioso in Bb by Haydn. (We have simplified it a little, to show just the melody.)
- The antecedent ends with an imperfect cadence in Bb (I-V).
- The last three notes in bar 4 are linking notes leading to the consequent phrase, and are not part of the cadence.
- The introduction of the E natural in bar 6 signals the beginning of a modulation to F major, the dominant key.
- The B natural in bar 7 does not signal a modulation to C major. Why not? Because the notes which fall on the beat in bars 7 and 8 are F-C-G-F – the Fs are prominent and the C and G are part of chord V in F.
- The phrase ends with a perfect cadence in F major, the new key (C-F).
Our final example is from a well-known Christmas carol, “It Came Upon a Midnight Clear”, set by Arthur Sullivan.
- There is no modulation from F major.
- The antecedent phrase ends with a chord IV followed by either a I or a V. This means it could be either a plagal or an imperfect cadence.
- The final cadence is perfect.
