Michael Gatt’s Étude Aux Chemins De Fer Analysis

Analyst's name: 
Michael Gatt
Year of analysis: 
Composition title: 
Étude Aux Chemins De Fer

This is an analysis that uses Pierre Schaeffer’s typo-morphology to define sound objects within the piece Étude Aux Chemins De Fer. The analysis also includes events and sections as an extension to typo-morphology to define how these objects relate within a musical framework.

Creation of Representation

Chion discusses three stages in applying the typo-morphology of sound objects within the Guide Des Objets Sonores: identification, classification and description (Chion 1994: 124). I used this methodology to segment and apply the typo- morphology analysis. For each of these stages I had to adopt a reduced listening approach to distance myself from the causality of the sound objects and focus on their functions and type. I also tried to add a musical dimension to the analysis, as typo-morphology only concerns individual sound objects and not their relation with one another. Something that Schaeffer admitted, as he did not have time to create a Traité des Organisations Musicales (Schaeffer 1966: 663).

I don’t believe that this is a definitive application of Pierre Schaeffer’s typo-morphology for this composition, rather it is my interpretation of both the work and the implementation of typo-morphology. I welcome any constructive criticism to revise this analysis.


The identification process was directly linked to the separation of sound objects by perceptual events and the sound object type. In the original version of this analysis I used the Acousmographe’s segmentation functions to map out these events and separating sounds into sound objects before applying the typology. The segmentation of Étude Aux Chemins De Fer was slightly easier than other modern composition, as there is only one stream of sound objects.

Classification – Typology

For reference here is the Typology table that has been translated from Guide Des Objets Sonores by John Dack and Christine North (2009): 

I struggled for a while to define certain objects within the composition as I felt that they could easily be identified with other typologies. This might have been because I struggled to grasp the key differences between certain types of sound objects, or the sound objects within the composition did cross boundaries. Regardless, I did define each sound object by type before considering their morphology. When I wasn’t sure on the overall sound type I could use the sound constituent level to identify any insufficiencies.

Description – Morphology

After I had defined the overall type for the sound object I then focused on describing its microstructure in order to describe its morphology. Schaeffer determined that each isolated sound object had its own microstructure that has its own unity, continuity, temporal envelope and reference to the typology of sound objects (Schaeffer 1966: 502). I defined this level as the sound constituents of the sound objects. Using Choin’s description of composed and composite criteria (Choin 1983: 156-7) I defined the morphology of each sound object.

Musical relation and structure

As stated previously typo-morphology does not concern how sound objects interrelate. To remedy this I defined a simple symbolic reference to describe how the sound objects interrelated. I defined these symbols as events. Please consult the table below for their terminology:



A cross-fade between sound objects where neither is stronger than the other. Also denotes a musical progression. 

The proceeding sound object cuts the previous sound object abruptly. Defined by a large change in dynamics and spectrum. 

The previous sound object cuts out abruptly to a weaker sound object. Defined by a large change in dynamics and spectrum. 

The proceeding sound object cuts the previous sound object abruptly, but they both share a similar intensity. 

Finally, I segmented the overall discourse of the composition into sections. These range from A sections, that deal with pitched gestural sounds, and B sections, that concentrate on mechanically iterative sounds. The base numbers define their relation to other sections that share a similar features and the exponent number is used to denote differences in these variations.

After this initial macro segmentation I noticed a pattern of variations from one section to another. I noted two main sections that use variations of similar material, which ultimately leads to a brief coda. This has been highlighted in the representation with the use of colour. This was something that I initially didn't hear (which I attribute to my musical memory of this piece);; however, after examining my segmentation I began to notice a pattern within the structure of the sound objects. Upon re- listening to the piece I began to hear these larger macro structures that I would have otherwise missed.

How to read the accompanying representation

The accompanying representation is split into two windows. The first is an overview of the entire piece. Within this first view you can see the segmentation of A and B sections and their relation to the overall macro structure of the piece (variation 1, variation 2 and coda). In the lower window, which offers a sound-by-sound view of the piece, is divided into four sections. Starting from the top there is the A and B segmentation from the first window for reference. Just below that there is the individual musical relations between defined sound objects (see table above). Then the sound objects are highlighted by colour (implemented within EAnalysis). Finally, below these there are the sound constituents that represent the sound objects morphology.



CHION, M (1994) Guide des Objects Sonores Paris, Buchet Chastel

SCHAEFFER, P (1966) Traté des Objets Musicaux Paris, Éditions du Seuil.