Ostinato and Variation forms
Part I - Ostinato Vzriations
Ostinato variations are continuous variation over a repeated bass line. This bass line is referred to as basso Ostinato (Ground bass). The most famous example of this is Pachelbel's Canon in D, Which is NOT canon form.
Fig.1 Canon in D ostinato bass
The Ostinato bass repeats as the harmonic melody changes over the top of it. A composer can be as unadventurous as to just have variations of a melody on top of the bass line. or go as far as to change the mode1 of themelody over the bass line.
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1. Mode- Any of various fixed orders of the various diatonic notes within an octave. i.e. Major, minor, etc.
Part II - Ostinato as a constructive device
The ostinato ovariations prevalent in Baroque music were replaced by theme and variations in the late 18th century. nineteenth century composers often used ostinato figures for effect, or as a compositional device.
Part III - Theme and Variations
Theme and variation form takes a familiar melody and uses it as a base for the entire piece. The subsequent variations will play with the melody or the bass line or both to create totally unique melodies.
Fixed Form Variations.
this is a technique that uses the melodic ideas and textures using the form and tonal structure of the theme.
Free Variations
Variations of the nineteenth century often abandoned the theme's formal structure. Themes were often subject to fragmentation, neaning that the varirations would often not use the entire theme. but rather only part of it to use as a base for the entire variation. Many composers found free variations attractive because they offered more chance to vary the original theme more widely.
Part IV - Organization of Variations
A typical outline of theme and variation looks something like this:
THEME VAR A VAR B VAR C VAR D VAR A VAR E
March Waltz Can-can Fugue
Notice that theme A keeps recurring throughout the piece.
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1. Mode- Any of various fixed orders of the various diatonic notes within an octave. i.e. Major, minor, etc.
Part II - Ostinato as a constructive device
The ostinato ovariations prevalent in Baroque music were replaced by theme and variations in the late 18th century. nineteenth century composers often used ostinato figures for effect, or as a compositional device.
Part III - Theme and Variations
Theme and variation form takes a familiar melody and uses it as a base for the entire piece. The subsequent variations will play with the melody or the bass line or both to create totally unique melodies.
Fixed Form Variations.
this is a technique that uses the melodic ideas and textures using the form and tonal structure of the theme.
Free Variations
Variations of the nineteenth century often abandoned the theme's formal structure. Themes were often subject to fragmentation, neaning that the varirations would often not use the entire theme. but rather only part of it to use as a base for the entire variation. Many composers found free variations attractive because they offered more chance to vary the original theme more widely.
Part IV - Organization of Variations
A typical outline of theme and variation looks something like this:
THEME VAR A VAR B VAR C VAR D VAR A VAR E
March Waltz Can-can Fugue
Notice that theme A keeps recurring throughout the piece.
