Output details

Nodewebba Software

Nodewebba is open source, generative-music software in which a web of feedback-based pattern generators creates dynamic, interlocking melodic and rhythmic patterns. Its underpinning principles (Variable-Coupled Map Networks, VCMN) have been developed and tested through further research and composition since I described the foundations of the technique in a 2004 article in the journal Organised Sound. Clonal Colonies was the first piece in which I used VCMN as a primary tool for generating material. The insights gained from this research process inspired and enabled the creation of Nodewebba, making the technique available to other researchers and to creators ranging from home studio users to professional musicians.

A node contains an iterated map function: a modified version of Lehmer’s Linear Congruence Formula. The scheduling of successive iterations determines rhythm. The state of the node is mapped to a chosen scale and range of scale steps and output as MIDI notes. The map state broadcast by a node can drive the variables, rhythm and duration values of any other nodes in the network, including itself. This can take the form of multiple levels of feedback and/or hierarchical control relationships. The emergent behaviour can be quite complex yet perceptually coherent. Parameters can be controlled via MIDI controllers. Configurations can be stored in presets. Variable handles are provided to allow coders to add their own routines to modify the behaviour of VCMN. Nodewebba rationalises start-up states, value wrapping, negative variables, variable range control, node broadcast-, iteration-, and update-scheduling techniques. This, combined with a carefully conceived timing scheme, provides consistently repeatable results, capacity to be synced with external sequencers, and an expanded range of control and behaviours beyond the original VCMN concept.