Consider the following two hypothetical dynamic gestures.

     The first gesture ("swell") consists of a crescendo followed
     by a diminuendo within a single measure:

                           |  <  >  |
                       ("swell" gesture)

     The second gesture ("dip") consists of a diminuendo followed
     by a crescendo within a single measure:

                           |  >  <  |
                        ("dip" gesture)

     We might have the intuition that "swell" gestures are more
     common than "dip" gestures.  But this raises two questions:

                1. Are "swells" truly more common than "dips"?
     and if so  2. WHY are "swells" more common?

Approach:

     In this demonstration, we will address only the first question:
     Are within-measure "swells" more common dynamic shapes than "dips"?

     Let's limit the problem by examining works by Johannes Brahms.

     We will examine the dynamic markings in 25 piano works, including
     sonatas, ballads, variations, intermezzi, fantasies, studies, etc.

     We can begin by defining pattern templates to be used by the
     PATT command.

     In the **dyn representation, hairpin crescendo and diminuendo
     markings are denoted by < and > respectively.  Barlines are
     represented by the equals-sign (=).

Here is the "swells" template:

          	=	(barline)
          	<	(followed by hairpin crescendo)
          	>	(followed by hairpin diminuendo)
          	=	(barline)


Here is the "dips" template:

          	=	(barline)
          	>	(followed by hairpin diminuendo)
          	<	(followed by hairpin crescendo)
          	=	(barline)

     Now apply these patterns to the sample of Brahms piano works.
     Count the number of occurrences of the pattern by piping the results
     through the Unix WC command.

     First using the "swells" pattern:

          patt -f swells brahms* | wc

     Number of "swell" gestures:     93

     And now using the "dips" pattern:

          patt -f dips brahms* | wc

     Number of "dip" gestures:       11

Conclusion:

     In this sample of piano works by Brahms, within-measure "swells"
     are much more common dynamic gestures than "dips."

Supplementary Question.

     Let's follow-up the apparent predominance of "swells" by asking
     whether the relationship to the barlines (i.e. meter) is important.

     For example, are "swells" ACROSS barlines less common than
     "swells" WITHIN a measure? i.e.

                             |  <  >  |
                       (within-measure"swell")

                              <  |  > 
                       (across-measure "swell")

Approach:

     Using the same sample of Brahms piano music, we will define
     an additional template:

Here is the new across-measure "swells" template:

          	<	(hairpin crescendo)
          	=	(followed by barline)
          	>	(followed by hairpin diminuendo)

     Now apply this new pattern to the Brahms sample.  Once again,
     count the number of occurrences of the pattern by piping the
     results through the WC command.

          patt -f swells brahms* | wc

     Number of across-bar "swell" gestures:    108

Recall:

     Number of within-bar "swell" gestures:     93

Conclusion:

     In this sample of music by Brahms, "swells" don't appear to be
     linked to the metrical context.  Swells are simply much more common
     dynamic gestures than "dips."