This is assignment 4 of the OCA Composing Music module 1: free counterpoint for two instruments and optional untuned percussion
I took the liberty of the untuned percussion being a single bell tuned to G
The whole piece is founded on mirrors about this note G, both strict inversion about this note and the use of scales in the octave above and below this note that are symmetrical (e.g. double harmonic minor in homage to Bartok and Hungary, but also whole tone scales a la Francais, and increasingly explicit references to Beethoven Op 133). The piece can be seen as referencing ‘continental drift’ through this fissure about G, or more sadly, the increasing fissures about and within Europe.
I used the alto flute liking its tone which I think will better balance the marimba than would a normal flute. This transposes down a perfect fourth. A pdf of a score follows and also some separate transposing parts, not at this point optimally laid out:
The Sibelius audio file is not perfect as it cannot represent the full practical range of the alto flute nor is it honouring all damping of the bell:
1-3 Inversion and statement of main subject simultaneously (double harmonic minor)
4-5 Restatement in alto flute alone with added octave displacement and alternation of theme across the two pitch levels
7-9 Countersubject (whole tone scales converging on the centre of the octave above G). Marimba extracts second bar of subject in augmentation
10-12 Chromatic inversion of subject about G in flute; marimba starts free counterpoint at bar 11.
12-19 Diminution, augmentation and inversion of the motif stated in flute at bar 16 which is drawn from the inverted countersubject centre of first beat bar 11, omitting lowest note
20-21 Third statement of countersubject, this time centred on and converging on G
22-23 Start of B section introduces the ‘Grosse Fuge’ countersubject and its inversion around G
24-25 Combination of this theme with chromatic permutation of the motif from bar 12
26-32 Episode with ‘stretto’ treatment
33-36 Combination of material from this episode with permuted version of the Grosse Fugue (countersubject) theme diminished or augmented
37-38 Compressed variant of call to attention as repeat of A section, but this time inverted
39-56 Chromatic inversion of section A in the alto flute part only ; marimba part strictly repeated (bars 3-21). Since bars 7,8 and 10,11 were themselves inversions these phrases now appear in reversed order and bar 20 inverted in bar 55 converges on the same note G, decorated with a ‘flourish’ in the flute leading into section C:
57-61. A free treatment of the ‘Grosse Fugue’ motif from bar 22, with triplet accompaniment in marimba also inspired by the Beethoven but much more chromatic. The various inverted forms die away, with alto flute using flutter tonguing.
63-73 Progressive intensification of chromatic triplet material
74 Final statement of the Beethoven motif in the flute, fff
75-77 Coda, flute picking from the two mirror forms of the main subject to state a final major cadence