@ted

These rhythmical features or counter-rhythms in much Baroque music give the music a kind of dynamic, energetic flavour. It is as if, instead of being content with lazily trudging on in always the same dull rhythm, the musicians have too much energy which they cannot refrain from letting burst out on regular intervals by throwing in a rhythmical somersault, after each of which they simply fall back with a straight face into the old rhythm as if nothing strange had happened. […]

These things therefore intruduce a temporary or ‘local’ deviation from the normal rhythm — temporarily, a ‘counter-rhythm’ is used.

Most often, these temporary ‘counter-rhythms’ occur periodically and regularly themselves, throughout the piece of Baroque music. That is, the changes in rhythm periodically repeat, and therefore there is incorporated in the music a pattern of rhythm which repeats over and over throughout the piece.