On Aug 24, 2011, at 5:42 PM, David Kastrup wrote:
> Mike Solomon <mike...@ufl.edu> writes:
>
>> Hey all,
>>
>> I'll be leaving on vacation in a week-ish, and as my summer-of-lily
>> comes to a close, I can likely do one more medium-scale thing before I
>> have to start correcting parallel fifths.
>> I'd like to work on broken beam slopes such that a beam can break
>> across lines and pick up where it left off at the same slope and
>> y-offset
>
> The problem I see with this approach is that one does not, in general,
> want the same slope and y-offset because it does not make sense to view
> the broken beam as a single visual entity.
All the pdfs associated with my response are up at
http://www.apollinemike.com/response_to_david
See chords2.pdf versus chords.pdf. In chords.pdf, I use an override to make
all beams flat. In chords2.pdf, I remove this override and let lily run her
course. I think that, in chords2.pdf, the disparity in slopes across line
breaks makes for really ugly typsetting. I would much rather have long stems
and continuity than more even stems and divergent slopes.
> Creating a single visual
> entity often means compromises like having over-long or -short stems in
> between. When "in between" moves right adjacent to the break, you don't
> want the stems there to be overlong and overshort just to make y
> positions match those of the next line. The next line is far away.
In the case of beams, I actually think people often want this. Check out
measure 6 of broken.pdf. I would gladly take a long stem before the line break
(the same length, for example, as that of the D natural in the previous beam)
such that the slope and Y-offset are continuous. I think that it is important
to make a scorer that can work on a per-line or all-line basis (like the one
I'm proposing) so that people can decide between the two with a property (Beam
#'preserve-slop-across-line-breaks).
>
> So you will generally want to preserve the beam slope roughly, and
> preferably the beam orientation.
I think that in the included PDFs, even roughly wouldn't work (I haven't tried
though) - as a performer, especially at fast tempos, the consistency of slope
would actually help me anticipate what is coming after the line break so that
my hands can move in the right direction.
> That means that if the unbroken beam
> would have a _knee_ at the break, you would, when splitting it, tend to
> prefer _unkneed_ beams with similar slope, even though that would mean a
> significant jump in y-offset.
Agreed.
> But that makes the visual connection
> easier to make than a jump in beaming direction.
>
Agreed.
> So thea esthetic decisions need to work under different constraints than
> in the unbroken case.
>
Agreed.
> We have the same "almost, but not quite as if unbroken" situation with
> slurs and ties. And it does not just occur with line breaks, but also
> in connection with repeats and da capo.
>
True, but I think these grobs are different because they hover over or under
early columns like clefs and key signatures, whereas beams start after these
columns. This allows beam continuity to be a lot better, as it does not have
to compete with the presence of a giant clef at the beginning of the barline
that would cause its y-offset to be very high or low.
> Do we have a sound general strategy for tackling this sort of controlled
> discontinuity? Maybe it would be worth thinking about.
>
Not really, although I'm way for this (my vector graphics spanner does this
sorta thing).
I think implementing this type of continuity for beams may be a good test case
from which a general strategy (if appropriate) can be extrapolated and applied
elsewhere.
Cheers,
MS
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