Handle: Engineering Artificial Musical Creativity at the “Trickery” Level - Computational Creativity Research: Towards Creative Machines - page 283

Fig. 14.2 Cognitive event calculus inference rules
to form hierarchical structures. We impose some constraints that stipulate that such
structures must correspond to some abstract syntax:
1. Events in music must have some syntax with which they can combine with other
events in music;
2. events inmusic must have semantics or meaning which interact with the meaning
of other events to produce a composite meaning for the whole musical piece.
To this end, we use a representation inspired by the Combinatory Categorial
Grammar approach to modeling meaning in natural and formal languages. (See [ 28 ]
for a quick introduction to the CCG formalism.) Informally, each word in a language
is assigned an expression in the typed lambda calculus. The types also specify one of
two possible directions in which the lambda function can take arguments. The types
allow certain parses of sentences to be ruled out. The meaning of a piece of text is
one of the many functional reductions that can be carried out.
The following example illustrates this. The word 'John' has syntactic type NP ,
that is, noun phrase, and has semantic value john ; similarly, 'Mary' has syntactic