Aphelion Concerto for Piano, Computer & Orchestra

Aphelion - The point in an orbit around the Sun at which an object is at its greatest distance from the Sun

Aphelion is a concerto for Piano, Computer & Orchestra based around sounds collected from planets and satellites in our solar system.  Scientists often translate the radio data they receive from celestial bodies into sound waves (a process called sonification) in order to understand better and interpret the data.  A number of samples were collected and manipulated for the current piece including radio signals from Saturn, remnants of the Big Bang, and a black hole.  In keeping with the celestial theme, Aphelion explores the concept of orbitation, through the use of cyclic themes and the sample of the satellite Sputnik which emerges from the texture at important structural points.

Work began on the concerto on the 2nd April 2007 with the majority of the work taking place in the studios at Royal Holloway University of London. The piece was written specifically for the MMus course but revised in September 2007 (completed 24th).

Tranquil

The opening movement was constructed around a chord sequence and system I had developed for a study piece I had written in November 2006. As part of the MMus course my class had been set the task of writing a piece of music based around the numbers 442434 and the chords Bbmaj7, Ebmaj7, Abmaj7. I had just read an article about Luigi Nono's Il canto sospeso and decided to employ a similar system he used. First a number row was created using the given numbers:

4 2 4 3 4 4 | 4 4 4 3 4 2

The second half of the number reflects the paired numbers of the first half. Next, a new row was created counting through the above sequence (cycled) and writing down every 5th number (the 5th number is 4, the next number counting 5 on is 3):

4 3 4 4 4 4 4 3 4 2 4 2

This became the prime row. To create another 11 rows based on the prime, the positioning of each number with in the row was examined. For example, the 2nd, 4th, 6th, 8th, 10th, & 12th (the even positioned numbers) are 3 4 4 3 2 2. These were noted along with the numbers that fell in the odd positions 1st, 3rd, 5th, 7th, 9th, & 11th): 4 4 4 4 4 4. Thus the second row became:

3 4 4 3 2 2 4 4 4 4 4 4

The second row was written below the prime:

4 3 4 4 4 4 4 3 4 2 4 2
3 4 4 3 2 2 4 4 4 4 4 4

To create the next ten rows, the above process was repeated (counting first the even, then the odd positioned letters) on each row in turn. The final time matrix was:

The three suggested chords were then written out in order :

I then counted through the sequence (starting at the bottom of the first column), noting every 5th note: Eb C F D Bb G Eb A Ab D Bb G. This was written against the time matrix:

To create a harmonic cycle, each pitch was written in a bar starting with Eb in the 1st bar (as its positioning suggests), C in the 2nd, F in the 3rd etc. This shall be refer to this as the pitches' original positions. In the picture below (click to enlarge) these notes are shown with diamond heads and quaver tails. Naturally, they fill the first 12 bars.

The number rows that created were used to set the distance between each reoccurrence of its given note. For example, the time row for the 2nd note (C) is associated with the number row 344322444444. 'C's' original pitch position is 2nd and so the 'C' first occurs in the second bar. The first number of its row is '3' therefore the note 'C' will occur after three bars' space (bar 6). To help explain, each note in the picture has been given a separate colour. Note that the red 'C' occurs in the 2nd bar (its original position in the grid), after three bars (bar 6) according to the number row, then after 4 bars (bar 11) according to the number row. Therefore, the number row for 'red' C (344322444444) and its initial positioning (2nd) causes the 'C' to occur in bars 2, 6, 11, 16, 20, 23, 26, 31, 36, 41, 46, 50, 55.

This process was applied to each note to generate the pictured pitch/time matrix.The pitch/time matrix was then used to create string pads for a the study piece I wrote called Serenity 442434 for Strings and Harp - written on 14th November. I decided to use the same 8-part string pad for the second movement of Aphelion. The cycle or notes (66 bars in total) are repeated 3 times with emphasis on different notes each time. The second movement is therefore in three parts although the piano part and the rest of the orchestra cover the joins. The piano first presents the main theme of the movement over the string pad and light electronic sounds based on radio waves from Saturn. The sound of Sputnik can be heard bridging the gap between the 1st and second sections. In the the second section, solo woodwind instruments explore the main theme whilst the piano performs in a rhapsodic style. The third cycle of the string pads begins around bar 38 whilst the piano and woodwind finish their ideas, the piano part then build up leading to the recapitulation of the main theme (b52). The computer sounds build up and fade away with the climax of the movement. Sputnik can then be heard again bridging the gap between the 2nd and 3rd movement.

Moto Perpetuo

Details to follow

Performance Instructions:

The computer part of Aphelion is controlled by Apple Logic.  A click track is provided for performance requiring the majority of performers to wear headphones of some type.  It is advised that only sections leaders, the conductor and every other desk of strings wears headphones and hears the click track.  The electronic parts include the aforementioned samples as well as synthesised sounds and pre-manipulated piano samples.  The electronic parts are represented in the score by cues.  These cues (labeled ‘Computer’) are just intended as a guide to the conductor.

The instrumentation:

Flutes 1 & 2 (doubling Piccolo)
Oboes 1 & 2
Clarinets 1 & 2 (doubling Bass Clarinet)
Bassoons 1 & 2
French Horns 1 & 2
Trumpets 1 & 2
Trombones 1 & 2
Vibraphone
Glockenspiel
Gong
Computer
Drum Kit
Piano Solo
Strings

The orchestra should be seated in the traditional layout.  A PA of sufficient wattage and quality is needed for live performance.  The speakers should be placed behind the orchestra in a manner to create the best stereo image for the venue.  It is advised that a controller operates Logic during the performances and uses a mixing desk to balance the output on the fly.  This can also be achieved in Logic by amending the automations or by routing the various tracks to different outputs.