Formerly all discords were prepared, and Monteverde’s innovation of
taking the dominant seventh unprepared was held to be cataclysmic, but in
modern music almost any conceivable discord may be taken unprepared. We
have grown so used to this now that we think nothing of it, still,
whenever it can be done without sacrificing something more important, I
think even a dominant seventh is better prepared.
It is only the preparation, however, of discords which is now less
rigorously insisted on; their resolution—generally by the climbing down
of the offending note—is as necessary as ever if the music is to flow on
smoothly.
This holds good exactly in our daily life. If a discord has to be
introduced, it is better to prepare it as a concord, take it on a strong
beat, and resolve it downwards on a weak one. The preparation being
often difficult or impossible may be dispensed with, but the resolution
is still de rigueur.