Tractus for two-channel tape (1997)

Duration: 8′

FP: Nov 12, 1997, Dresden

Further performances:

a.o. Nov 13, 1998, Helsinki (Finnish premiere)


The word ‘Tractus’ is of Latin origin, meaning an ‘even, permanent motion’. The composition is based on a permanent structure, consisting of thirteen overlapping layers which are related to prime numbers between 5 and 47. This structure is never audible as a complete period – a period up to the full sound of all 13 layers would, at 240bpm, last more than 7 years. Instead, inner periods (including different shades of sound and diverse positions in the panorama) are made audible in different layers. Respectively first intersections of two, three or four layers have firstly been emphasized as an accentuated point, later as a lingering chord. Initial and end points of changing parameters like volume, ambit, tempo and micro-tonal detuning have been located in regard to these interceptions. Furthermore, same has been done with arrangements of sections and their processes of development. Thus, the first greater section is – in face of its fast repetitions – static and of increasing tonal compactness within very little space. In contrast to the first part, the later and also shorter parts feature an expansion of tonal space leading to an abrupt change of development. This change brings about very calm resting sounds shaping the piece’s character. Although this last event seems to dramaturgically round the composition, it is only a quite short excerpt out of an unbelievable long time lapse. As a whole, this is not at all intended to be esoteric – to the contrary: ‘Tractus’ has been a specific attempt to write a tape composition, which strongly distances from the too napless aesthetic conceptions of most electronic music. At the same time this piece might be regarded as reminiscence to B.A. Zimmermann’s only tape composition Tratto.

The basic sounds have been created using the simple additive synthesis software ’softsynth’ before being reworked with ‘Turbosynth’ and ‘Sounddesigner’. Afterwards, the whole work has been completely composed via ‘GraphicComposer’, which has been developed in the electro-acoustic studio of the Dresden Music Academy.