Operator Theory

Summary Operators are the substance of shaping performance. They refer to mothers, but they are the only instances capable of altering, refining, or ruining what has been achieved. They are also the pipes where exterior information, be it from score predicates, from analytical data, or from general system parameters, can be channeled and transformed into performance structures. We describe and motivate the concept of a weight (function). This is the turning point between “exterior” and “interior” strata to performance. We discuss different exigences for performance operators to cope with `primavista’ and ‘analytical’ data. A series of common primavista and analytical weights is discussed. We then expose a taxonomy of operators, fol­lowed by some special examples of the existing realizations, regarding tempo and articulation, as well as theoretically founded generalizations which are based upon Lie derivatives. The chap­ter concludes with a discussion of more “social” types of operators which correspond to “family life” correlations introduced in section 38.3.4. The final subject is a prospective to ‘continuous stemmata’, i.e., generalized stemmata based upon infinitely small coupled space portions.