joakim sandgren




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i have used a composition tool called compose, programmed in lisp, to make all my compositions since 2003. this text outline the organization of this composition tool.



  • the formal compositional work take place in something i call a proportional space.


  • the proportional space is a serie of units.


  • all units have a length of one.


  • the proportional space can be divided into smaller spaces called fields.


  • a field has a length of at least one unit.


  • the total number of units that constitute a proportional space is called the resolution of the proportional space.


  • every field in a proportional space correspond to a sound or a silence in the score.


  • the sound or silence objects in a score is are represented by one or more score symboles.


  • the score symbols are either notes or rests.


  • the notes and pauses does not correspond to the fields in the proportional space.


  • a field can be represented in a score by several notes, and even in advanced cases by complex structures made of combinations of notes and pauses. but it remains a single sound or silence.


  • there is no correspondence between the number of units in a field and the number of notes in the corresponding sound or silence in the score.


  • the score structure is made of sections, partial sections, measures and partial measures.


  • a partial measure correspond to a conductor beat.


  • every measure have a measure time signature.


  • every partial measure has a partial measure time signature.


  • every measure has at least one partial measure.


  • example: a 6/8 measure beaten on every dotted quaver is then a measure with a measure time signature of 6/8, made of two partial measures with a partial measure time signature of 3/8.


  • there can be several partial measure time signatures in one measure.


  • to be able to work in the proportional space i first need to know its resolution.


  • to know the resolution of a proportional space i have to construct that resolution.
    this is done by making a nominal score.


  • a nominal score is an empty score where i have decided how many nominal objects it can be in every partial measure.


  • the nominal objects in a partial measure are of the same length.


  • the number of nominal objects determine the nominal resolution of that partial measure.


  • a nominal object correspond to one unit in the proportional space.


  • if i count all the nominal objects in a nominal score i will have the total number of units of the proportional space.


  • thus, the total number of nominal objects in the nominal score corresponds to the resolution of the proportional space.


  • once I have the resolution of the proportional space i can start the formal compositional work.


  • the temporal aspect of the formal compositional work is to divide the proportional space into nested fields.


  • once these divisions are made the proportional space is now organized in a hierarchical content (that correspond closely to the "contenu formel" of G. G. Granger: formes opérations objets).


  • the bottom field in a hierarchical content at a given position is the active field.


  • an active field can be either a sound or a silence.


  • once i have the hierarchical content I can ask for its active fields.


  • once i have the active fields i can now lay out them on the nominal score.


  • i now have the raw score of the composition.


  • once i have the raw score the rhythmical structure is subject to a extended series of transformations in order to have the final rhythmical structure.


  • these transformations now take place on the score structure and is no longer related to the proportional space method. i am thus changing to another set of rules.


  • when i have the final rhythmical structure I have the final raw score. this is how far the composition tool take the structures of the composition.


  • all transformations made in the score after the production of the final raw score is made by hand.


  • paris, le 3 mars 2012