Live recording of the Première of my piece for Cello and Live Electronics at the Chimera Concert in the Sir Jack Lyons Concert Hall on 27th February 2015.

Featured in Leeds IFiMPAC 2016

Programme Notes:

Ground Zero (2014) presents a reflection on images of the ongoing Syrian civil war. The electronics function entirely to modify the sound of the Cello, making this piece very much a duet as the phrasing is dependent on complete synchronisation between the two. The development of the harmony, which makes functional use of the 24-note microtonal chromatic scale, is mirrored by developments in the spectrum of the final sound produced by the cello and electronic modulation, creating a strong link between harmony and timbre. The generative material for the music in Ground Zero is the natural harmonic glissando.
There are many aspects to this sound and these are all expanded upon over the course of the piece: 

- Rapidly fluctuating sound as the harmonics constantly change.

- A constant sense of the fundamental pitch which can be perceived even through all these harmonics.

- The pure, sine wave-like sound of the harmonics.

- The brief patches of white noise which occur in between harmonic nodes.

- The glissando.

Performers:

Cello - Miri Nohl
Electronics - Omar Peracha

'Ground Zero' (2014) - Cello & Live Electronics

Live recording of my piano trio, 'Udyana', at soundSCAPE festival 2016 in Maccagno, Italy.

Performers:

Flute - Christina Raczka
Cello - Felix Fan
Piano - Thomas Rosenkranz

Programme note:

Commissioned by soundSCAPE new music festival, 'Udyana' is a reflection on a trip I made to Swat Valley, Pakistan, while it was still under Taliban Control. The true beauty of the landscape conflicted with the sense of threat; at times one sensation would overpower the other, or else both were simultaneously experienced in a strange paradox. The piece aims to capture and present some of these moods.

The musical material mostly consists broken chord-type figures and glissando-type gestures, which develop fairly freely and organically to serve the dramatic shape. The harmony is derived from spectrally analysing the piano's bottom C, including it's full decay phase, generating a pitch set which evolves and grows smaller throughout the piece.

'Udyana' (2016) - Piano, Flute & Cello

Premiered by the Sleeper Society at the Chapter Arts Centre, Cardiff, in January 2017. Featured in NYCEMF 2017 and SBCM 2017. Awarded 2nd prize in the UnTwelve 2018 Microtonal Music competition.

'Colour Etude I' is the first in a series of pieces exploring the strict application of certain spectral techniques influenced by the research of William Sethares, while keeping all parameters except for harmony very simple. These pieces function as a means to test harmonic concepts, and to create more accessible examples of microtonal and spectral music by leaving most aspects of the piece uncomplicated; the form of the piece is essentially theme and variation.

An 11-partial waveform was generated in Supercollider using random numbers for the partial frequencies and amplitudes, which were then tweaked to taste. The entire piece uses instances of waveforms with these same ratios between the frequencies of their 11 partials - i.e. exact transpositions of the same waveform. In a particular 'key', only notes whose fundamental frequencies occur in the spectrum of the 'tonic' can be used, leading to a series of 11-pitch sets which modulate between each other via common pitches.

'Colour Etude I' (2016) - Electroacoustic

Studio recording of my piece for bass oboe and fixed media, 'Ground Zero II.

Bass Oboe - Nicola Hands


Programme Notes:

'Ground Zero II' is the second piece I've written reflecting on the Syrian civil war; two years after 'Ground Zero' the picture had changed significantly, with the emergence of ISIS and the refugee crisis as prominent global topics.

Unlike 'Ground Zero', the electronic element in this piece is not live but a fixed tape part. The piece is constructed using harmony and melodic writing derived from the spectral analysis of a bass oboe multiphonic. Pitch classes used are almost entirely from the spectrum, with all microtonal pitches appearing in the tape part only as we simply hadn't worked out enough microtone fingerings to use them freely in the bass oboe! The opening melody consists of an ascending minor third (E to G) and a descending major third (G to Eb), of course leaving a semitone (Eb back to E) to complete the interval vector of this motif. The motif is developed by expanding it outwards to gradually include the rest of the pitch classes derived from the multiphonic's spectrum, using similar shapes and restricting horizontal intervals entirely to the three mentioned.

The piece plays with perspectives of scale; the opening sections focus entirely on development using the mode derived from the multiphonic's spectrum; the middle section features a multiphonic chorale, 'zooming out' of the one multiphonic and including pitch classes from outside its spectrum, though the horizontal intervallic consistency, itself still derived from the prominent pitch classes of the original multiphonic's spectrum, is maintained. The perspectives are linked by playing a melody derived from the opening motif above these same multiphonics sounding in the tape part. There is also a small element of further 'zooming in' on the three original pitches of the motif and melody, focusing on their spectra, whose prominent pitch classes also occur in the generative multiphonic spectrum.

This piece required research to be carried out, which I did with the help of oboist Michael Sluman. Together, we recorded a whole range of the bass oboe's sounds, all of which I then spectrally analysed in what I believe is the first such research to be carried out on the bass oboe. The collected data is available here: https://omarperacha.com/bass-oboe-spectral-data

'Ground Zero II' (2016) - Bass Oboe & Electronics

Live recording of the premiere of my piece, 'Colour Etude II', at IKLECTIK Art Lab in London, 18 March 2017.

Performed by Xenia Pestova & Késia Decoté. Recorded and mixed by Saint Austral Sound.

Video: https://www.youtube.com/watch?v=yYLWej-s064

Programme Note:

'Colour Etude II' was commissioned by keyboardist Xenia Pestova. The piece is scored for one or two toy pianos and live electronics. It was premiered as a duet by Xenia and Késia Decoté in March 2017, at a concert in London.

The piece is the second in a series exploring the strict application of certain spectral techniques influenced by the research of William Sethares, after 'Colour Etude I', this time with an added emphasis on improvisation. It makes use of two pitch sets; one from the spectral analysis of a toy piano's C4 (middle C), and one from its F4. The electronic components of the piece consist of two procedurally-generated and evolving soundscapes derived from the the analysed spectra, which provide the backdrop for the piece, and a sampler which contains toy piano notes tuned to pitches from these spectra that would otherwise be unplayable (microtones and notes in an extreme high register).

The electronics can be wholly controlled using the 'Colour Etude II: Live Electronics' iOS application, freely available for iPad & iPhone, which greatly streamlines the equipment requirements of this piece and increases portability. Alternative options are available, including a Supercollider patch to control the soundscapes and an EXS24 file for the sampler.

The score provides a series of text instructions, pitch restrictions and some notated examples to structure and guide the player's or players' material throughout the piece, therefore also providing the overall shape. Beyond this, everything is improvised.

Get the app for free here and try out some of the sounds from the piece: https://itunes.apple.com/us/app/id1206150318

'Colour Etude II' (2017) - Toy Piano(s) & Live Electronics

Ex 2

Ex 3

Ex 4

Ambient piano-based track for Daylight Music at Union Chapel, 31st March 2018. Written using Google Magenta's pianoroll_rnn_nade model.

Daylight Music

Studio Recording of 'Transients and Latent Spaces' for beatboxer.

Programme Note:

'Transients and Latent Spaces' is my first work exploring the applications of deep learning and generative AI to concert music composition. Two deep models from Google's Magenta project were used as part of the compositional process: drums_rnn and MusicVAE.

I trained the drums_rnn model on drum patterns based on rhythms from The Sacrificial Dance, the final movement of Stravinsky's Rite of Spring which brings to the forefront many of the rhythmic devices employed by Stravinsky throughout the rest of his piece. These drums patterns were obtained by manually adding an accompanying drum part to sections of this movement, trying to match the rhythmic accenting of the original work as accurately as possible. This model was used to generate various sections of material which functioned as structural 'pillars' of the piece.

The MusicVAE model, trained on a massive corpus of drum beats from popular music, was used to interpolate between these 'pillars' of Stravinsky-influenced material generated by drums_rnn, in a way that was smooth-sounding yet also used natural and idiomatic beat patterns.

Recorded and performed by myself, July-August 2018

'Transients and Latent Spaces' (2018) - Solo Beatboxer

'I' from 'Four Short Accidents' for piano (2018) 

These four short movements were entirely generated by a deep neural network, which I had in fact built to serve another purpose; the AI was supposed to learn to model 3-6 part vocal music of Palestrina, a task on which it clearly performed very poorly.

That said, albeit unintentionally, the output was still very interesting to me. It generated movements with a consistent form: an opening quote from Palestrina's corpus before cascading chordal phrases, pausing on a few long, sustained chords. There may follow more cascades and pauses, before the movement converges on a single note.

The model demonstrates some understanding of voice leading logic, albeit in a style far more contemporary than Palestrina's, and how to highlight and move between certain focal pitches and gestures, which gives shape to the music.

Omar Peracha

Popular tracks