Contemporary music composition is a highly creative and disciplined activity that requires free expression of ideas and sophisticated computer programming. This paper presents a technique for structured observation of expert creative behavior, as well as Polyphony, a novel interface for systematically studying all phases of computer-aided composition. Polyphony is a unified user interface that integrates interactive paper and electronic user interfaces for composing music. It supports fluid transitions between informal sketches and formal computer-based representations. We asked 12 composers to use Polyphony to compose an electronic accompaniment to a 20-second instrumental composition by Anton Webern. All successfully created a complete, original composition in an hour and found the task challenging but fun. The resulting dozen comparable snapshots of the composition process reveal how composers both adapt and appropriate tools in their own way.

Seeking sound samples in a massive database can be a tedious and time consuming task. Even when metadata are available, query results may remain far from the timbre expected by users. This problem stems from the nature of query specification, which does not account for the underlying complexity of audio data. The Query By Example (QBE) paradigm tries to tackle this shortcoming by finding audio clips similar to a given sound example. However, it requires users to have a well-formed soundfile of what they seek, which is not always a valid assumption. Furthermore, most audio-retrieval systems rely on a single measure of similarity, which is unlikely to convey the perceptual similarity of audio signals. We address in this paper an innovative way of querying generic audio databases by simultaneously optimizing the temporal evolution of multiple spectral properties. We show how this problem can be cast into a new approach merging multiobjective optimization and time series matching, called MultiObjective Time Series (MOTS) matching. We formally state this problem and report an efficient implementation. This approach introduces a multidimensional assessment of similarity in audio matching. This allows to cope with the multidimensional nature of timbre perception and also to obtain a set of efficient propositions rather than a single best solution. To demonstrate the performances of our approach, we show its efficiency in audio classification tasks. By introducing a selection criterion based on the hypervolume dominated by a class, we show that our approach outstands the state-of-art methods in audio classification even with a few number of features. We demonstrate its robustness to several classes of audio distortions. Finally, we introduce two innovative applications of our method for sound querying.

We present paper substrates, interactive paper components that support the creation and manipulation of complex musical data. Substrates take different forms, from whole pages to movable strips, and contain or control typed data representations. We conducted participatory design sessions with five professional musicians with extensive experience with music creation tools. All generated innovative uses of paper substrates, manipulating their data, linking multiple representation layers and creating modular, reusable paper elements. The substrates reflect the structure of their computer-based data, but in a much more flexible and adaptable form. We use their prototypes to provide concrete examples of substrates, identify their roles, properties and functions. Finally, we explore their physical and interaction design with an interactive prototype.

OpenMusic is an open source environment dedicated to music composition. The core of this environment is a full-featured visual programming language based on Common Lisp and CLOS (Common Lisp Object System) allowing to design processes for the generation or manipulation of musical material. This language can also be used for general purpose visual programming and other (possibly extra-musical) applications.

We present score programming features in the visual programming and computer-aided composition environment OpenMusic. The sheet object allows to build complex scores and fill or modify their contents algorithmically using visual programs.