Kilka uwag o ezoterycznej naturze izorytmii

Abstract

In musicologlcal literature one can find contradictory opinions about the esoteric character of the isorhythmic motet. H. H. Eggebrecht, G. Reichert and R. H. Hoppin do not agree with the opinions expressed by H. Besseler and U. Günther, who state that the sensory perception of isorhythms is impossible. It seems that the conflict originates in the differentiation of the range of the repertory, the analysis of which has become the base for general opinions. The research carried out by various scholars in various periods of time show some different specific qualities of the isorhythmic formation; they expose to various degree the technical means (especially the hoquet with a motorial culmination) which make it possible to hear the isorhythmic form. Besseler analyses the isoperiodic motets of F. de Vitry of those times. The construction of their motets shows a loose connetion with the isorhythmic structure of tenor. Hence the form of such compositions is usually illegible in the auditory perception. The hoquet groups have an essential form-creating role in the motets by Machaut which were studied by Reichert and by Eggebrecht which are usually partially isorhythmic and the form of which does strictly depend on the formation of cantus firmus. They favour the formation of a clear formal plan which is possible to be heard. The complete isorhythmic motets from Manuscript 564 from the Bibliothèque du Musée Condé at Chantilly and from Manuscript a. M. 5, 24 from the Biblioteca Estense at Modena were analysed by Günther. They show an extreme complication of the rhythmical contrapunctal process and of very lengthened isorhythmic periods. The formal frames become blurred and difficult to perceive. Hoppin has also analysed certain completely isorhythmic motets from Manuscript J. II. 9 from the Biblioteca Nazionale at Turin. In these motets there is a simplified rhythmic relation accompanied by increased motorial centrast within the isorhythmic periods which gives a more distinct expressiveness to the composition's structure, and this in consequence can be more easily perceived by the senses.