  Out of the scope of the usual positions of computing in the field of music
and musicology, one notices the emergence of human-computer systems that do
exist by breaking off. Though these singular systems take effect in the usual
fields of expansion of music, they do not make any systematic reference to
known musicological categories. On the contrary, they make possible experiments
that open uses where listening, composition and musical transmission get merged
in a gesture sometimes named as ?music-ripping?. We will show in which way the
music-ripping practices provoke traditional musicology, whose canonical
categories happen to be ineffectual to explain here. To achieve that purpose,
we shall need: - to make explicit a minimal set of categories that is
sufficient to underlie the usual models of computer assisted music;- to do the
same for human-computer systems (anti-musicological?) that disturb us; - to
examine the possibility conditions of reduction of the second set to the first;
- to conclude on the nature of music-ripping.
