Cadences in the Classical style are fairly generic (i.e. they use standard patterns that fit nearly all situations). Write a few simple cadences in the same key, tempo etc as your Basic Idea. You can always come back to this stage if you need more cadences later in the process, but getting the basics done first is worthwhile.
First you should write a perfect cadence in the tonic for the very end of your theme. This needs to be strong and emphatic and therefore should be as follows:
- V – I in root position
- final note on the first beat of the bar
- melody ending on the tonic note of the key (1)
- melody moves by step onto this last note (notes of the scale: 2-1 or 7-8)
(Americans call this sort of strong perfect cadence a perfect authentic cadence)
Most cadences are an elaboration of one of these two patterns:
The way the actual cadence is approached tends to follow a small number of standard patterns – the most common three are shown below. Choose one of these patterns and decorate a little without spoiling the finality of the cadence. As in these examples, the whole cadence should be around a bar onto the final note of your phrase.
||Haydn Piano Sonata, Hob IX No. 20/8, first movement
This simple cadence has a few decorations of the basic 3-2-1 pattern.
Basic melody options: 3-2-1 or 8-78
ii6 – V – I
|Haydn String Quartet op. 33/1, second movement.
Approaching the perfect cadence from chord ii6 is very common – here the chord before is VI but it could just as well be i or i6.
Basic melody options: 2-2-1, 8-78 or 2-7-8
V-I (with a cadential 6/4)
|Haydn String Quartet op. 33/3, second movement.
Haydn decorates chord V with a cadential six-four. It is very common also to use ii as an approach to this cadence pattern
Basic melody options: 3-2-1 or 8-7-8
You may need some other types of cadence elsewhere in your phrase. You will probably want to come back to this page when you have decided what structure you are using and therefore what cadences you need.
The two most common imperfect cadences are I-V and ii-V. In this example from the last movement of Haydn’s String Quartet Op. 33 No. 5 the dominant chord (V) is preceded by ii in first inversion and decorated with a cadential 6/4.
Perfect cadences that are NOT at the end of phrases can we weaker, with different inversions and melody notes. In this example from Mozart’s Piano sonata K545 the cadence at the end of the fourth bar is on a weaker beat and ends on the third note of the scale: