Sometimes, musical analogy says it well:

The playing of some virtuosos is like the gait of a drunkard. Make not such your models.

.. and ..

There are no wrong notes, only wrong resolutions.

.. and ..

A good musician can make mistakes as long as they seem like they were planned, and evoke amazement and beauty by intentionally making what seems like mistakes, only to resolve them later, when no one is expecting it.

see also: rules for young musicians