The analytic, Anglo-American tradition of philosophy typically defines qualia as what is left after all objective aspects are subtracted from experience, i.e., qualia are the subjective feeling tones of experience; the usual examples are feeling tones of atomic perceptions, such as a patch of red, for which the quale is "the redness of red." I believe that this definition is much too narrow, as well as highly misleading.
Qualia are phenomenological, because tehy are based on human experience, so the only way to understand them is to examine human experience carefully. Such an examination shows that qualitative experience cannot be separated into distinct subjective and objective components, and that embodiment and immersion in the world are necessary aspects of experience. Very similar insights can be found in continental phenomenology (e.g., Husserl and Heidegger), Gestalt psychology, and areas of modern cognitive science, especially cognitive linguitics.
Building on these insights, this project defines qualia to be salient chunks of human experience, which are experienced as unified wholes, having a definite, individual feeling tone. Hence the study of qualia is the study of the "chunking," or meaningful structuring, of human experience. An important, and seemingly new, finding is that qualia can have complex internal structure, and in fact, are hierarchically organized, i.e., they not only can have parts, but the parts can have parts, etc. The transitive law does not hold for this "part-of" relation. For example, a note is part of a phrase, and a phrase is part of a melody, and segments at each of these three levels are perceived as salient, unified wholes, and thus as qualia in the sense of the above definition - but a single note is not (usually) perceived as a salient part of the melody. Moveover, qualia can involve simultaneous perceptions in different sensory modes, sequences of perceptions, emergent properties of blended perceptions, and complex emotions; also, sensory and conceptual discrimination limitations, short and long term memory, and other factors arising from concrete embodiment with a particular sensory and mental basis, play an important role in the phenomenology of qualia.
The flow of time, the change or motion of experience through time, and the anticipation of change seem to be crucial for understanding qualia. For this reason, music is an excellent site for studying qualia, as several works listed below demonstrate. The first describes some experiments with simple musical stimuli that establish claims made in the previous paragraph, along with many others. The second paper proposes a theory (or model) of qualia that uses an "energy" function based on a novel structural hierarchical theory of information, such that the most desirable structures for qualia have minimum energy; this use of a complexity measure as energy makes ideas from nonlinear dynamical systems theory applicable, including phase space, bifurcation, and chaos. In addition, a generalization of blending, in the sense of cognitive linguistics, is used to explain how qualia are composed and transformed in complex structures, and an evolutionary explanation for the emotional aspect of qualia is given. The third and fourth papers describe applications of this theory to free jazz improvisation; we consider this the beginnings of a new musicology, suitable for contemporary musical and multimedia forms (as well as older forms). The sixth item is an artistic expression of some ideas from qualia theory, and the final two items are abstracts from an early stage of this project. The fifth item is the abstract for a workshop to be held at the 2006 Towards a Science of Consciousness conference. The sixth item is an artistic expression of some ideas from qualia theory, and the final two items are abstracts from an early stage of this project.