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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 better understand and interpret the data.  A number of samples were collected and manipulated for the current piece including radio signals from Saturn, and 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 places.

 

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 my MMus course although only the 2nd and 3rd movements were submitted - the 1st movement was not complete for the deadline and the work as it already existed (movements 2 and 3) was over the 8 minute target for the assignment. The piece consists of two large sections: 'Tranquil' & 'Moto Perpetuo'. Both were completed on the 1st May 2007 with the introduction being added and the piece revised in September 2007 (completed 24th).

Tranquil
The second 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. The first thing I did was to make up a number row using the given numbers:

424344 | 444342

The second half of the number reflects the paired numbers of the first half. Next, I created a new row counting through the above sequence (cycled) and writing down every 5th number I landed on (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 my prime row. To create another 11 rows based on the prime, I examined the positioning of each number with in the row. For example, the 2nd, 4th, 6th, 8th, 10th, & 12th (the even positioned numbers) are 3 4 4 3 2 2. I noted these down and then worked out the numbers that fell in the odd positions 1st, 3rd, 5th, 7th, 9th, & 11th): 4 4 4 4 4 4. Thus my 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, I repeated the above process (counting first the even, then the odd positioned letters) on each row in turn. The final time matrix was:

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

With the three chords, I wrote them out in order:

A
F
D
Bb

D
Bb
G
Eb

G
Eb
C
Ab

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:

1st
Eb
4
3
4
4
4
4
4
3
4
2
4
2
2nd
C
3
4
4
3
2
2
4
4
4
4
4
4
3rd
F
4
3
2
4
4
4
3
4
2
4
4
4
4th
D
3
4
4
4
4
4
4
2
4
3
2
4
5th
Bb
4
4
4
2
3
4
3
4
4
4
4
2
6th
G
4
2
4
4
4
2
4
4
3
3
4
4
7th
Eb
2
4
2
4
3
4
4
4
4
4
3
4
8th
A
4
4
4
4
4
4
2
2
3
4
4
3
9th
Ab
4
4
4
2
4
3
4
4
4
2
3
4
10th
D
4
2
3
4
2
4
4
4
4
4
4
3
11th
Bb
2
4
4
4
4
3
4
3
2
4
4
4
12th
G
4
4
3
3
4
4
2
4
4
4
2
4

To create a harmonic cycle, I wrote out each pitch in a bar starting with Eb in the 1st bar (as its positioning suggests), C in the 2nd, F in the 3rd etc. I shall 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.

Note Matrix for Apheliom

The number rows that I 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 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 this, I have coloured each note in the picture. You will see 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 (bb4-22) 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 would be 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 used is:
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.

Last Updated: September 25, 2007