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notes on the keyboard part of Enclosures by Peter Adriaansz Bob Gilmore, October 2010 Enclosures for voice, viola, MIDI keyboard and sine tones was composed in June-‐July 2008 for Trio Scordatura, who premiered it at the TRANSIT Festival in Leuven, Belgium, on October 25 that year. Although it is perfectly possible to perform the keyboard part simply from the information in the score, the following notes are provided as a documentation of the first realization of the part, as heard in the early performances of the piece by Trio Scordatura and in our studio recording, made in December 2008. The player will need to programme both the sound and the array of pitches for each of the three sections of the piece in advance of the first rehearsal, so the suggestions given here, reflecting consultation with the composer during the rehearsal process, may hopefully speed the preparation of the part by a player coming new to it. I perform the keyboard part of Enclosures on a five-‐octave MIDI keyboard connected (via USB) to a soft synth programme on a laptop. The design described here uses Native Instruments’ Absynth 3, which I have used in all the performances of the piece until now, but almost any soft synth programme could be used. The player also needs a volume pedal to fade in the held chords at the beginning of each of the three sections. In addition, I found a small weight – a 6.5 x 4 x 4 cm piece of stone which looks like marble (but is in fact probably something else) – was essential to play the sustained pitches in movs 2 and 3, leaving my hands free to play the other lines. I made three patches, one for each section of the piece, and these will be described in turn. In performance there is plenty of time between sections to switch between them. Section I The intention here is a relatively thin sound (the sound for the subsequent two sections becomes gradually fuller). A pure sine wave by itself seemed too thin, so I made an “organ” patch with five sounding harmonics, the fundamental (1st), 2nd, 4th, 8th, and 16th. Purely on the basis of taste I made the higher harmonics relatively strong so the sound has a kind of “graininess” at the top (which also helps the ear to distinguish it from the sine tone patch). The picture below shows the spectrum:
Spectrum of the sound for section I, showing the relative intensities of harmonics 1, 2, 4, 8 and 16.
Each individual sound crescendos slowly from p to mp, sustains, and diminuendos back to p again. This needs to be programmed in the waveform. The shape I used is shown below, in two parts:
and
Waveform of sound for section I: the sound crescendos in, over 3.25 seconds, can then be sustained indefinitely and, on releasing the key, decrescendos out again over slightly more than 4 seconds. I made a mapping of the pitches used in section I (thirteen in all) onto the keyboard as follows (the fourth note shown here, A-‐880 Hz, is in fact not used in the movement, but is useful as a reference):
Mapping of pitches onto the keyboard in Enclosures I. Section II The intention here is a fuller, “darker” sound. The patch uses three oscillators corresponding to harmonics 1, 2 and 4. The relative intensities of the three oscillators can be seen in the picture below. This is perceptually a richer sound than that used in section I. The envelope is very similar to that shown above for section I, building from nothing to its full volume around 3.25 seconds, sustaining, and dying away over about 5 seconds. At the beginning of section II the weight (the block of “marble” described
above) is placed on the lowest C and D on the keyboard, which are tuned respectively to D-‐146.7 Hz and D-‐293.3 Hz. These are sustained throughout the movement.
Patch of the sound for section II, showing the relative intensities of the three oscillators In section II, during the rehearsal process, Adriaansz decided to add three very low tones into the texture, opening up the sort of “sound chasms” found in some of his other pieces of this time (e.g. Waves 11-13). All three tones are slightly detuned Ds: 36.33 Hz, 72.6 Hz and 73.33 Hz. (For comparison, conventional tempered Ds in those octaves are 36.71 Hz and 73.42 Hz). This creates a slow, rather ominous beating. The exact placement of these notes is somewhat free: I have tended to introduce the two higher tones (72.6 Hz and 73.33 Hz) somewhere after 9’, and the very low tone (36.33 Hz) around 9’ 40”; they are sustained and then released in reverse order somewhere after 12’. The mapping of the other sixteen pitches onto the keyboard is shown below:
Mapping of pitches onto the keyboard in Enclosures II. Also used are five “drone” pitches as described above - C and D at the bottom of the keyboard (146.7 Hz and 293.3 Hz), and the D, Eb and E keys in the gap in this diagram (36.33 Hz, 72.6 Hz and 73.33 Hz).
Section III This is the most dense section of the piece and the most complex microtonally. The patch uses two oscillators, the second quieter than the first and tuned an octave below it. This gives a rich, but not “heavy”, organ-‐like sound, with some upper harmonics audibly present. (The patch I ended up with was actually somewhat “thinner” than my initial attempt, as the volume of sound produced by the keyboard in this movement can become overwhelming.) The patch is shown below:
Patch of the sound for section III, showing the relative intensities of the two oscillators The envelope is very similar to that in the previous sections of Enclosures. In section III again the weight is placed on the lowest C and D on the keyboard, sustaining pitches of F#-‐185 Hz and G-‐392 Hz throughout the whole section. Initially Adriaansz suggested that the increments between consecutive notes on the keyboard may be either 1 or 2 cents; I programmed both versions, but in rehearsal we found that the beating resulting from intervals of 1 cent was too subtle to be effective, and so decided on increments of 2 cents. The mapping of pitches onto the keyboard in this section is the most complex in the piece. My suggestion is shown below:
Mapping of pitches onto the keyboard in Enclosures III. In performances of Enclosures a second laptop is needed to run the Supercollider patch for the sine tones; this also provides the players with a large stopwatch.