Comment #1 on issue 2449 by [email protected]: Redesign stream event class representation
http://code.google.com/p/lilypond/issues/detail?id=2449
Ugh, that's really ugly. Dispatchers internally call ly:make-event-class and are, more or less, supposed to be an abstract construct not related to layouts, contexts or anything. So it would appear that the concept of non-constant event class relationships involves a serious redesign of a _lot_ of things. This task really gets uglier and uglier.
It is, actually, the existing code that is ugly and hard to change.
