Manuella Blackburn's Valley Flow Analysis

Analyst's name: 
Manuella Blackburn
Year of analysis: 
Composition title: 
Valley Flow


Denis Smalley’s Valley Flow was composed in 1991 during his time spent at the Banff Centre for the Arts in Canada. Influence for this work is drawn from the vast and dramatic vistas of the Bow Valley in the Canadian Rockies (Smalley 2004). The changeable environment of this place is captured through a switching of perspectives throughout the work. Smalley describes “the listener, gazing through the stereo window, can adopt changing vantage points;; at one moment looking out to the distant horizon, at another looking down from a height, at another dwarfed by the bulk of land masses, and at yet another swamped by the magnified details of organic activity”(Smalley 2004).

The most noticeable feature of Valley Flow is the flowing gesture the work is built upon. This gesture has an almost constant background presence, but is by no means subliminal, for its fluidity and variety of forms provides interest, in addition to a strong evocation of the environment. The gesture’s continuity provides a backbone function, upon which more foreground sound materials interact, causing changes in texture.


The aim of this analysis is to reveal interactions between background and foreground sound materials. Identifying perceptually the positioning of sound materials seeks to aid the revelation of their interactions. As a consequence, the analysis also aims to illuminate the significance of sound positioning in effective spatial conveyance.

Spectromorphology and spectral density

Denis Smalley suggests a descriptive tool based on aural perception to overcome the lack of any significant procedure to analyse electroacoustic music. Smalley calls this tool ‘Spectromorpholgy’. The two parts of the term refer to the “interaction between sound spectra (spectro) and the ways they change and are shaped through time (morphology).” (Smalley 1997: 107). This tool proposes a way of thinking about the sounds we hear and suggests a terminology for describing these events as comprehensively as possible.

In conjunction with the ideas of spectromorphology, I will use examine the sound’s spectral depth positioning with the extremes of depth regarded in this case being ‘near’ and ‘far.’ In the way we may consider spectral space to be represented by an x/y axis, we may consider spectral density to be a three-dimensional extension of this concept.


Smalley’s own descriptive tool of spectromorphology will be applied to Valley Flow in order to reveal interactions between sound materials and to examine spectral density use. The sonogram will be used in conjunction with spectromorphology to provide a visual representation of the identified sounds material interactions. The work will be divided into segments of one- minute duration that will be subjected to sonogram and spectromorphological analysis. Interactions will be considered in terms of their spectral density positioning and will be identified in the sonogram via annotations.


0 - 1.00: The fundamental sound of the piece is presented in this first minute. This morphology has a streaming, flowing quality, while its directionality is initially presented as linear with a graduated continuant archetype. Around 0.11 seconds the streaming morphology is stated again, following a brief silence. The continuant of this morphology is prolonged through an ascent while displaying an increase in intensity. The texture increases and remains monomorphological. Our spectromorphological expectation is increased due to the morphology displaying directionality, thus we are aware the sound is leading to an event. In this first minute we encounter the conveyance of spectral depth as we are aware of the concept of distance, since the streaming sound appears to be ‘far away’ in the background. The lack of any rooted occupancy in spectral space and the isolation the streaming sound is placed in, results in an impression of emptiness. 

1.00 – 2.00: There is further growth of the texture due to the presence of previously unoccupied levels in spectral space and increases in intensity. The motion continues to ascend, converting our expectation to tension for the ascent has been prolonged for almost a minute. A peak is never formally reached but a partial reciprocation occurs in the form of an iterative descending morphology that appears to grow out of the streaming sound.

Here we encounter the first example of background/ foreground interaction. The causality of the iterative descending morphology is loose, leading to an eventual (as opposed to immediate) foreground gesture. This foreground gesture has strong source bonding to falling rocks which fall to rooted points in spectral space. They are short in attack, and closeness in terms of spectral density contrasts to that of the streaming morphology. This fall acts as a termination through release to the onset that began at 0.11 seconds.

2.00 – 3.00: The previous agglomeration of rock sounds decreases to small fluctuations of separate attack impulses. The background streaming sound reappears momentarily before leading to a pulsating iterative wind sound that also lies in the background. At 2.31 a sharp foreground attack onset occurs, triggering an ascending flying morphology, again through causality. This is another example of background/foreground interaction, this time the foreground downbeat appears to be causal of the returning streaming background sound. 

3.00 – 4.00: During this minute we are made aware of morphological phrasing constructed with carefully placed silences. At around 3.05 a sharp attack instigates a re-sounding decay morphology at a lower point in spectral space, after interrupting the streaming morphology. Turbulent motion is experienced as variants on the streaming morphology are sounded. These are multidirectional, shown in the sonogram as overlapping bands of the streaming sound, criss-crossing over each other and preventing a collective motion. Without a clear sense of direction, spectromorphological expectation becomes ambiguous as we are unable to establish where the sound is leading to.

4.00 – 5.00: The overlapping multidirectional behaviour continues, this time there is greater emphasis on a descending shape articulated with further intensity. A more background morphology leads to the occurrence of a foreground sharp attack, prolonged through resonance interacting in a causal relation. This attack functions as a downbeat for further foreground causalities. A sound source bonded to heavy rain follows. This texture appears to occupy a much higher point in spectral space due to the absence of any rooted sounds.

5.00 – 6.00: From the previous texture emerges the returning iterative descending morphology that leads to several rock sound agglomerations. The background descending motion from the previous minute is reprised, overlapped with more foreground rock sound agglomerations. 

6.00 – 7.00: The spectral focus is shifted around the canopy level of spectral space. The multidirectional streaming morphologies appear to fly passed each other in a return of the turbulent texture, again creating ambiguity in expectation. The iterative descending morphology emerges as a continuant to the multidirectional morphologies, appearing to grow out of this sound (6.18). The texture is built from layers of overlapping morphologies that are derivatives of the fundamental streaming sound. Lower level pitched drones, multidirectional sounds and the iterative descending morphology remain in the background while the streaming plane shapes take on greater intensity to appear at a more foreground position.

7.00 - 8.00: The texture in this minute is streaming, constructed from multiple planes, representing a calm ambient environment. The focus remains on the canopy area of spectral space until 7.41 where a burst of multidirectional behaviour occurs twice with greater intensity promoting these morphologies to a more foreground position. 

8.00 – 9.00: There are several foreground attacks which are unsuccessful in triggering any causality so can be considered as false attacks. This is a tension building device as we have previously heard foreground attacks cause subsequent behaviours and thus we are expectant of similar sorts of behaviours. An attack at 8.48 finally triggers a change in texture source bonded to rain and stony sounds. The masking effect of this texture on more background sounds is due to its foreground position and majority coverage in spectral space.

9.00 – 10.00: The texture presented in the previous minute is abruptly terminated by an attack. The sounds previously masked beneath the foreground texture continue beyond the attack, with a noticeable spectral focus on the streaming sound. A climax is reached around 9.29 where the streaming morphologies increase in frequency and intensity. This climax is prematurely terminated by a foreground attack triggering a steep descending sound. The streaming morphologies disappear, while flickering stony sounds return as the perspective shifts to an empty distanced viewpoint.

10.00 – 11.00: The flickering rock sounds gradually disappear upwards shown on the sonogram by the decrease in lower spectral space occupancy. A single streaming sound emerges from this shift from a close to far away perspective. Following a pause, the streaming sound returns, taking on bolder, iterative characteristics. The descending iterative morphology again emerges from the streaming sound. 

11.00 – 12.00: The iterative descending morphology overlaps the streaming sounds. The streams now occupy a closer position promoted to a more foreground level as they overlap further back morphologies. The streams can be seen to cut across a small rock agglomeration sound occurring at 11.44.

12.00 – 13.00: Streaming morphologies are prolonged and begin gradual ascent.

13.00 – 14.00: The ascent does not lead to a foreground event as it has previously. Multidirectional motion becomes apparent. The streaming morphologies begin to descend, accompanied with a more background texture that displays a parabolic motion. 

14.00 – 15.00: The first foreground attack instigating a granular texture constructed from gritty, stony sounding attacks varying in intensity. The dense texture conveys strong source bonding to the environment’s more hostile characteristics, such as harsh wind and rain. Another foreground attack triggers the iterative descending morphology. A further attack prompts the return of harsh wind, rain and rock sounds with greater intensity.

15.00 – 16.00: The manner in which the iterative descending morphology is triggered by the foreground attack in the previous minute is repeated twice in this following minute. Streaming multidirectional behaviour returns at around 15.42.

16.00 – 16.48: The piece ends with a monomorphological texture symmetrical to the opening minute, here the streaming morphologies descend and disappear in the distance, concluding the journey we have been taken around the valley. 


The behaviour of background sound materials leading to foreground events in a loose causality manner appeared to be the most prominent interaction type revealed from the methodology. Interactions of triggering, overlapping, interrupting and phrase sharing between background and foreground sound materials were also identified. A typology can be established from the sonogram sound shapes, allowing every sound presented in Valley Flow to be categorized as one of nine sound shapes. Further study of the typology allows a further reduction of the sound shapes to two sound types, distinguished on the basis of their spectral density positioning;; background streams and foreground attacks outlined in the following tables.

Streaming sounds

Sound shape 


Fundamental sound. Streaming plane with graduated continuant archetype. Sustained sound forming background texture. Acts as continuing thread, which the piece is built around. 

Descending iterative morphology. Derived from fundamental sound. Usually forms loose causality with leading behaviour. 

Multidirectional bands of fundamental which criss-cross in ascending/descending patterns. Results in turbulent sounding texture. Create air of ambiguity as we are unaware of direction our spectromorphological expectation is uncertain. Tension building device. 

Separate attack impulses linked with stream. Rare in occurrence. 


Sound shape 


Sharp attack. This sudden onset spans extremities of spectral space. Can be triggered or trigger for subsequent causal behaviours. Also functions as an interruption or interpolation. 

Falling rocks agglomeration. Internal texture constructed from many individual attacks, which form an overall collective falling motion. Archetype is a graduated continuant (extrinsic). 

Attack decay archetype. Acts as a termination for larger scale sound shapes/textures. 

Granular rain-like sound. Texture made from closely packed attacks. Alterative texture to streaming sound (providing contrast) dissipating spectral space. Morphology has textural opacity as effluvial criteria block out detail. 


Sound shape 


Arc shaped morphology constructed from a series of similar shapes. Positioned in the background masked by more foreground morphologies. Belongs to a series of similar morphologies with overlapping entries. Cannot be isolated from overlapping morphologies. 

It became apparent that the positions categorizing the sound types were, by no means restrictive. For example streaming morphologies defined by their background positioning could be promoted to a more foreground level through taking up characteristics of increases in intensity, duration, iteration and multidirectional behaviour.

The arc shaped morphology tabulated in the ‘other’ category emerges as an anomaly within the analysis. The shape’s consistent background position and the absence of rooted occupancy in spectral space prevent it’s categorisation as an attack, while it does not resemble any similarities to the streaming sound. It is arguable however, that the established typology here does not appear to accommodate this sound shape and is a short fall of the systemization in this instance. 



SMALLEY, D (2004) Impact intérieurs empreintes DIGITALes, IMED 0409, (cd liner-note).

SMALLEY, D (1997) Spectromorphology: explaining sound-shapes, Organised Sound, 2 (2), pp. 107-126.