This article introduces the concept of Sound Signature audio visualization, a new form of amplitude waveform that also visualizes perceptually salient spectral features and their evolution over time. A brief review of existing research into timbre description and visualization is given. This is followed by an in-depth description of the algorithm. Rationale is given for the various visual mappings with reference to existing literature. The results of an online subjective evaluation survey are reported and discussed. The survey examined user preferences for the visual mappings used in Sound Signature visualizations. Results show a preference for inverse mapping of spectral centroid to the first component of the hue, saturation, value (HSV) color space.

In this article, we present a set of musical transformations based on the representations of chord spaces derived from the Tonnetz . These chord spaces are formalized as simplicial complexes. A musical composition is represented in such a space by a trajectory. Spatial transformations are applied on these trajectories and induce a transformation of the original composition. These concepts are implemented in two applications, the software HexaChord and the Max object bach.tonnetz , dedicated to music analysis and composition, respectively.

String players spend a significant amount of practice time creating and learning bowings. These may be indicated in the music using up-bow and down-bow symbols, but those traditional notations do not capture the complex bowing patterns that are latent within the music. Regular expressions, a mathematical notation for a simple class of formal languages, can describe precisely the bowing patterns that commonly arise in string music. A software tool based on regular expressions enables performers to search for passages that can be handled with similar bowings, and to edit them consistently. A computer-based music editor incorporating bowing patterns has been implemented, using Lilypond to typeset the music. Our approach has been evaluated by using the editor to study ten movements from six violin sonatas by W. A. Mozart. Our experience shows that the editor is successful at finding passages and inserting bowings; that relatively complex patterns occur a number of times; and that the bowings can be inserted automatically and consistently.