Composition of Two-Part Inventions

In my first test of using repeated transformations, I wanted to create a dramatic and slightly dissonant feel, and as such, have made a theme of the ‘Devil’s interval’ of a diminished fifth, mainly based around C and Gb.  What struck me when composing with the use of transformations was the simplicity and ease of it all.  By creating just two bars of a melody, I was able to use a number of different techniques to create a much longer piece, keeping a familiar flow and feel, whilst varying textures throughout. 

In my first example I have used augmentation (seen in the first bassoon bar and first and second timpani bars), diminution (third and fourth bassoon and third of timpani) and imitation transposed to a diminished fifth (bars six & seven of both instruments).  I later added the cymbal line to add more dramatic effect to the piece.  I wanted the dynamics of this piece to feel slightly unbalanced and growing in volume to increase the feeling of drama.

In my second attempt at two-piece inventions, the theme is a little more complex, but with a mainly smooth and steady flow, backed by the gentle tempo of 76bpm.  I chose to compose this piece in Bb minor and used the flute and glockenspiel to reflect the light and airy nature of the piece.  As in the above piece, I have used diminution and augmentation, but this time I have experimented with diatonic inversion at the octave, retrograduation and a simplified form of imitation and rhythmic imitation. 

The fifth bars of the flute show diminution of the third and fourth bars and the sixth is an inversion of the fifth bar.  This pattern is later repeated by the glockenspiel but slightly adjusted to fit within the range of the instrument.  The glockenspiel's fifth and sixth bars are augmented and inverted in the flute’s seventh – tenth bars.  I then retrograded these four bars in the 11^th to 14^th bars of the flute.  In bars fifteen – eighteen I have simplified the imitation by composing a unison melody, then changing the first note of each beat to a crotchet.