Not in the notes: Erlkoenig as a case study in Human Computing

A companion paper (Paper 1) argues the need for a radically different perspective on computing that is particularly relevant to its role in the humanities. A key notion is dispelling the idea of an absolute duality in experience, and reinterpreting computing with respect to distinctions that rest on how experience is characterised. We can understand how this might work by recognising that semantic relations similar to those that arise in computer programming exist in the humanities. The pianist plays Chopin, but the score resembles a program. But where the computer scientist views the program as essentially defined by its precise abstract operational semantics, the musician — whether composer, pianist or analyst — takes a much more liberated view of the meaning of the musical score. The pianist is deemed to play a Chopin sonata, even though there are some wrong notes. Playing Chopin and playing the piano are both human skills that clearly admit no exact ultimate level of attainment, and the counterpoint between the two is a commonplace theme in music analysis and criticism. Particularly pertinent in this context is Mahler's remark that "what is best in music is not to be found in the notes" (Shapiro), and the well-attested fact that Chopin's use of rubato defied precise notation in a score (Schonberg).

A better understanding of the distinction between a musical score and a conventional computer program helps us motivate an alternative approach to computer-based modelling that can do fuller justice to the concept of humanities computing — that of Empirical Modelling (EM). The archetypal computer program is intended for machine interpretation, and is optimised for a specific function and context of use. Though the results of executing the program can be experienced by the human interpreter in the appropriate user role, any human interpretation of the program in execution is in general a most specialised exercise in interpreting machine operation that is of its essence unintelligible within the context of use. What is more, the degree of specialisation and optimisation of the program to function is typically such that the user-oriented interpretation disintegrates on changing the merest detail — all that remains to the programmer is to debug the behaviour of the machine. Contrast the musical score. Though the aspiration of the pianist may be to trace the execution from beginning to end with the strictest adherence to the score, the process of interpretation resembles reading a computer program no more than it resembles reading a piano roll for a player-piano. (Indeed less, since in this analogy a computer program is typically more like a prescription for punching holes in a piano roll.) The pianist may enter the score at any point in time, extract melodic fragments, or adapt the written prescription in order to savour the experience of a particular chord, to shape the inflection of a melody, or identify the essence of a technical difficulty. In this activity, in accordance with Mahler's dictum, the pianist will give ultimate priority not to being in every respect accurate to the score, but to evoking and communicating the felt experience. In the spirit of Turner, the separation between the technical accomplishment and the musical effect is not a sharp duality: the two experiences of playing the piano and playing Chopin are blended in the experience of the human interpreter. The priority that is given to those aspects of the interpretation of the score that are least precisely documented is reflected in the way that we say: "She played Chopin's Revolutionary Study" rather than "She used the piano to execute Chopin's Revolutionary Study." This distinction between stances towards interpretation speaks to a yet deeper tension between the values of the humanities and the method-tool-use paradigm of the business IT culture (EM-website 055).

The principles of EM, and the respects in which they represent a radical departure from conventional thinking about computing with implications for the humanities, can be illustrated with reference to a study in modelling music. For this purpose, our choice of theme is Erlkoenig, as first dramatised in verse by Goethe, then set to music by Schubert, and later transcribed by Liszt for piano solo. The objective for this case study is to show how the application of EM principles and tools is suited in principle to the development of an auxiliary model that can serve a whole variety of different functions for the human interpreter. At present, the construction of such a model is in its earliest stages, but its broad conception can be outlined by drawing upon well-established experience of EM for a wide range of applications (EM-website, EM-archive). An important and characteristic theme of EM that echoes sentiments expressed about modelling by McCarty (2004) is that the potential scope and function of the model cannot be preconceived, nor will the model ever represent more than "a temporary state in the process of coming to know." In this respect, it is crucially different from a conventional program in having no preconceived formal specification, and being intended and open for indefinite extension and elaboration.

The case study has been chosen to highlight a number of key issues: the fundamental significance of the shift in perspective towards the radical empiricist outlook of William James (1996) rooted in the idea that 'one experience knows another'; pertinent aspects of EM from a technical modelling perspective, such as the role for observation, dependency and agency, the scope for invoking concurrent agents in the interpretation, and the merits of EM in respect of combining models; how each of the six varieties of modelling identified by McCarty (2004) can be represented within a single EM model.

The importance of a radical empiricist stance stems from the need to account for a treatment of meanings in the humanities that is far beyond the scope — though not perhaps the aspirations — of the formal semanticists in computer science and AI (Smith 1987). Consider the audacity of the following extract from Maurice Brown's commentary on the Erlkoenig: "Even more remarkable, as was first pointed out by Sir Donald Tovey in a superb programme note on the song, is the treatment of the pianoforte when the childspeaks. During the rest of the song we are observers: we watch the ride, we hear the child's voice and the father's reassuring answers. But only the child hears the Erlking, and the rocking, almost lulling, movement of the pianoforte accompaniment is the child's experience of the motion of the galloping horse, the warm protection of his father's arms, while he trembles at the sinister invitation. When he cries out, we revert to observers and the clamour of the hoofs, the rush of the wind, break again on our ears." (Brown)In Jamesian terms, both Brown and Toveyare testifying to the experience of a conjunction of two experiences (the texture of the musical accompaniment and the child's perspective on events) for which no formal explanation need be given. It is quite characteristic of such a conjunction that its recognition is to some extent enabled by a purely technical consideration — that these changes in texture come as a enormous relief to the accompanist, so taxing is the pianistic device that evokes the horse's unrelenting ride.

From a technical modelling perspective, Erlkoenig is a rich source of instances of agency, dependency and observation. EM makes use of techniques for distributed modelling (cf. EM-archive: claytontunnelSun1999) and animation (EM-archive: railwayYung1995) that can underpin concurrent engineering (EM-website: 034). The model-building can be framed with reference not only to the various perspectives of external agents (in this context, the poet, the composer, the singer, the accompanist, the translator etc) but also those internal to the drama itself (the father, the child, the Erlking, the horse). A vital aspect of EM is that model construction is not compromised by optimisation to performing some specific function, as in conventional programming, so that blending of models is pervasive, and there is openness to extension possibly even in the light of subsequent developments in tools and technology (cf. the new pianistic possibilities explored by Liszt in his transcription of Erlkoenig).

The status of EM as a radical generalisation of modelling with spreadsheets makes it possible to envisage a role for modelling extending that illustrated by McCarty in his Analytical Onomasticon to Ovid's Metamorphoses (2005, Chapter 1). Musical counterparts for the analogy, representation, map, diagram, simulation and experiment can be found in modelling Erlkoenig and identified in EM. Of particular interest is the combination in the context of a music of formal and informal semantic frameworks. One might for instance seek an authentic virtual reconstruction of an early performance of Erlkoenig as Schubert himself might have heard it (cf. Beacham), or wish to elaborate on the semi-formal analysis of musical language of Erlkoenig that Cooke initiates in (Cooke). A precedent in EM for combining formal and informal semantic ingredients within a single model can be found in (EM-website: 051).