There are two names for Ground Bass pieces - chaconne and passacaglia. The distinctions are worth noting and certainly exist in plenty of examples. However, composers have not always used the names correctly, so their meanings have become blurred. A chaconne is a series of unbroken variations invented on a recurring chord progression. Indeed, the 'theme' is the chord progression itself. A passacaglia has a more melodic bass line rather than a prescribed series of harmonies. The theme is 'singable'. Passacaglias tend to be in a slow triple meter.
Below is an example of Pachelbel's ground bass. Pachelbel wrote numerous melodic variations over this ground bass:
In its earlier form, developed in the 13th and 14th centuries, the ground bass never varied in harmonisation or pitch. Such example is the earliest known use of the ground bass ‘Sumer Is Icumen In’ (between 1240 and 1325).
This type of variation was developed in England in the 16th century. It was particularly popular in the 17th and 18th centuries and was used extensively in the Baroque era. This type of composition was written for the court (royalty and nobility), the church and the theatre. Pacific types of music were played in theatres are the opera and oratorio. Secular music was non-religious (written for the court and theatre). Sacred music was written for religion (the church).
Purcell in particular made frequent and masterly use of the ground basses, for example ‘Dido’s Lament’ in ‘Dido and Areneas.’ J.S. Bach and Handel also made remarkable use of it.
Variation
Musical variation may vary the melody, harmony or rhythm of a stated theme wholly or in part, by embellishment, by simplification, or by contrapuntal harmonic or rhythmic elaboration.
The composer takes a simple tune and then repeats it many times, each time making certain changes. Characteristically, the piece may open with the statement of a simple theme that is then elaborated in various ways.
The variations usually keep the same basic structure as the theme (i.e. the same number of bars, same number of phrases and mostly the same chords) and some of its melodic features, but each variation will introduce new twists and changes. Variety may be introduced into the variations in the following ways: purely melodic decoration, motivic development and changes in harmony, rhythm, metre, tempo, texture, instrumentation, mode and key. Often, the variations will become progressively more elaborate as the piece develops. At the end of a set of variations the original theme might be restarted, or there may be a long coda. Sometimes there is a long section.
In a set of variations:
- The tune can be decorated with extra notes and ornaments (such as trills)
- The rhythm of the tune can be changed, and/or the metre (number of beats to a bar)
- The tempo (speed) can be changed
- The harmonies can be changed (concords to discords or vice versa)
- The mode can be changed from a major key to a miner key or vice versa
- The tune can be put into the bass or into an inner part
- The tune can be presented in imitation, fugato or canon (change of texture)
- A noticeable change of timbre can be made
- The tune can be turned upside down (inversion)
- The tune can be absent whilst the harmony or/and rhythm are kept as a remainder
- A counter melody (one which fits with the tune) can be added
- Some of the notes in the tune can be taken away, keeping just the most important ones.
- The rhythm of the tune can be changed, just stretched out (augmented) or squashed by using shorter note values (diminution)
A theme may be old, new or even borrowed from another composer. Whatever the source, the theme needs to be easy to recognise and fairly simple. There can be as many variations as the composer likes.
An example of variations includes “Rhapsody on a Theme of Paganini.” Sergei Rachmaninoff turns the tune into the major and upside down so that it becomes very hard to spot. Another example is Haydn’s “Emperor Quartet.” Using his own tune “Glorious things of thee are spoken” the tune simply passes through each instrument quite openly.
Variation is one of the oldest forms of European instrumental music used by composers when writing music. It was popular in England as long ago as the reign of Queen Elizabeth I and since then has been used by many great composers. It was particularly popular with the 16th century keyboard composers. Variations movements are found in works ranging from String Quartets to orchestral pieces. They have been written for most solo instruments. It is found through all periods of music.
Ternary form
A study of pieces, which fall into three clear sections; the middle section will differ from the outer sections. The middle section will provide some kind of contrast. It could be in a different key, often the dominant of the first section (a perfect fifth above). Or it can be played on a different musical instrument. Less commonly, the trio may be in a different time signature (for example, 3/4 as opposed to 2/4 of the march). We describe the overall effect as an ABA pattern. The contrasting second section is often known as a trio. Think of it as a sandwich, if you can hear a “filling” (a different middle section), then it is in ternary form.
The B section can be contrasted in the following ways:
- The tune can be decorated with extra notes and ornaments (such as trills)
- The rhythm of the tune can be changed, and/or the metre (number of beats to a bar)
- The tempo (speed) can be changed
- The harmonies can be changed (concords to discords or vice versa)
- The mode can be changed from a major key to a miner key or vice versa
- The tune can be put into the bass or into an inner part
- The tune can be presented in imitation, fugato or canon (change of texture)
- A noticeable change of timbre can be made
- The tune can be turned upside down (inversion)
- The tune can be absent whilst the harmony or/and rhythm are kept as a remainder
- A counter melody (one which fits with the tune) can be added
- Some of the notes in the tune can be taken away, keeping just the most important ones.
- The rhythm of the tune can be changed, just stretched out (augmented) or squashed by using shorter note values (diminution)
There are many examples of ternary form tunes among simple nursery rhymes, traditional or folk songs and carols. The nursery rhymes “Twinkle Twinkle Little Star” and “For he’s a Jolly Good Fellow” are examples of ternary form as the tune at the beginning is repeated at the end.
Other examples include Ode to Joy by Beethoven, Tinga Layo (Calypso from the West Indies), An Eriskay Love Lilt (Folk song from Scotland) and The Skye Boat Song (A Highland rowing song)
Musical forms of this kind are exceedingly effective. You can find them everywhere, in simple tunes or in elaborate movements. Different contrasts are achieved through use of changes in mode, rhythm, tempo, dynamics, mood and texture. Many compositions in ternary form feature the D.C. al Fine mechanism. These are easily identified since the Fine will usually accompany a double bar-line in the middle of the piece.
In the 18th century operas and oratorios, the most common type of solo song was played in ternary form called the da capo aria. Ternary form has a long history and is found in much Baroque vocal music in the da capo aria, as well as marches and many dance forms such as the polkas written by the Strauss family.
A dance in ¾ time that was very popular in the 17th and 18th centuries. Minuets generally consist of 2 sections: a minuet and a contrasting trio. Both sections are usually in binary form, and the minuet is usually repeated after the trip giving an overall effect of ternary form.
Rondo form
A rondo is a musical form, which develops the idea of contrast and repetition that we find in ternary form. The Rondo opens with a lively tune or ‘subject’ and this returns several times during the course of the movement. Contrasting passages known as ‘episodes’ separate the various returns of the main tune. The main tune always returns in the same key. The episodes modulate to different keys. This form can therefore be described as an ABACADA (EAFA etc.) form. The number of themes can vary from piece to piece, and the recurring element is sometimes embellished or shortened in order to provide for variation. Think of it as a club sandwich (lots of different fillings between the slices of bread).
Characteristically, music in rondo form has a section that recurs and alternates with contrasting episodes/sections. Contrast is achieved through changes in modes, rhythm, tempo, dynamics, mood and texture. Rondo form is also characterised by links between episodes and codas.
The episodes can be contrasted in the following ways:
- The tune can be decorated with extra notes and ornaments (such as trills)
- The rhythm of the tune can be changed, and/or the metre (number of beats to a bar)
- The tempo (speed) can be changed
- The harmonies can be changed (concords to discords or vice versa)
- The mode can be changed from a major key to a miner key or vice versa
- The tune can be put into the bass or into an inner part
- The tune can be presented in imitation, fugato or canon (change of texture)
- A noticeable change of timbre can be made
- The tune can be turned upside down (inversion)
- The tune can be absent whilst the harmony or/and rhythm are kept as a remainder
- A counter melody (one which fits with the tune) can be added
- Some of the notes in the tune can be taken away, keeping just the most important ones.
- The rhythm of the tune can be changed, just stretched out (augmented) or squashed by using shorter note values (diminution)
Examples include “Für Elise”, “The Entertainer” and “Rondo alla Turca.”
The form began to be commonly used from the classical music era, although it can be found in earlier works. Movements of this kind are frequently found in the keyboard music of the 17th and 18th centuries, and as last movements in sonatas and symphonies by Hayden and Mozart. It was a development of ritornello form from the Baroque period. The last movements of solo concertos are also frequently in rondo form. A development of rondo form in the Sonata-Rondo Form, which, as its name implies, combines features of both forms. Beethoven’s movements usually have this added complexity.