That Goodbye is an elaboration of the first verse from the poem “Do not go gently into that goodnight” by Dylan Thomas, read by the author .
The idea of ​​this piece is to develop techniques such that the words slowly disappear becoming pure sound.

I was always been fascinated by echo. But echo is a repetition (almost) identical to the original. In “That Goodbye” I adopted some processing techniques whereby the echo returns modified more and more with each repetition.

These techniques consist in inserting a processing device inside the delay loop that generates the echo. So the effect grows with each repetition and the audio fragment changes more and more than the original.

This way of composing is quite far from traditional techniques. Here, I select processes that generate long-lasting results. The composition, at this point, is equivalent to the choice of sound fragments and the processing through which they must ‘roll’.

Some examples [please note: in order not to force you to listen to half an hour of examples, all the loops are accelerated with respect to their use in the piece, in the sense that the delay is very short (about 1 sec.) And therefore the repetition frequency is high so the transformation takes place within a few seconds].

• Processing: reverb
  In this example, the accumulation of reverberation at each loop cycle produces an increasingly long halo so that the reverb gradually “eats” the sound, reducing it only to the resonance frequencies excited by the input. The connection with the initial fragment remains in agogic form. The result depends both on the frequencies present in the input and on the resonant frequencies of the reverb.
• Processing: filter
  At each loop the input is filtered with a unity gain band-pass, which leaves only the center frequency unchanged and attenuates all the others. The sound gradually simplifies until a single sinusoid remains.
• Processing: flanger
  The flanger effect increases with each repetition, resulting in beats of increasing complexity.
• Processing: ring modulator
  When the modulator placed on one of the harmonics, the ring modulator expands the spectrum and changes its balance at each loop cycle.

That Goodbye begins with Dylan Thomas’s voice passing through a bank of 8 band-pass filters and is splitted into as many independent audio streams.

Each of them then slips into a delay line with time different from the others (from about 5 to about 12 seconds). The cut-off frequencies and the bandwidth of the filters are not regularly spaced, but have been calibrated on the bands of greatest signal activity and range from 100 to 5000 Hz.

In this first part of the piece the processing element in the loop is mainly the reverb which lengthens the sound and transfigures it by destroying the words and transforming it into frequency bands of differentiated pitch. The low and middle bands have longer reverberation times (up to 6-8 seconds) and quickly create background sounds over which the higher elements move.

In the second part some of the final transformation from the first part are sent to delay lines with different processing, especially flangers, filters, ring modulators and envelopes. The last two generate some bell-like sounds deriving from the spectral transformation of the medium-high bands and from the application of an envelope that at the beginning is linear and merges with the rest, but becomes more exponential and more percussive.

Towards the end of the second phase, a third phase starts which begins on the low bands to which are applied delay with ring modulator and pitch shift starting a scaling of the harmonics expanding with each loop cycle.

This part is resolved in a fourth and last phase that moves backwards in the piece by looping the results of various convolutions between the original phrase and fragments taken from the three previous phases creating a series of ghosts of the starting fragment.

Mauro Graziani – That Goodbye (2002)