[MEI-L] How to use <ftrem>

[TW]

2011/6/17 Roland, Perry (pdr4h) <pdr4h at eservices.virginia.edu>:
>
> If we explicitly set the number of beams and slashes, then for 16th notes it would be beam="2" slash="1", which is redundant.  But this would also allow for 16th-note tremolandi to have some other, "incorrect" number of slashes, just as half notes appear to frequenty have.

Mh, what's an incorrect number of slashes?  A consistent rule for
beams and slashes would be:  Beams+slashes represent the repetition
frequency (or more precisely the "stroke frequency").  Beams alone
represent the overall duration of the tremolo.  This would mean that
notes longer than an eighth would only get slashes.  But that's not
common practice (only Heussenstamm mentions this possibility).

> The repetition frquency can be derived from the combined values of @beam and @slash, but in order to provide complete independence it could be stored in another, new attribute.  This provides the greatest flexibility, but is redundant in most cases.
>

Maybe we have the cart before the horse.  Instead of specifying the
number of beams alias "connecting slashes", we could specify the
number of "hovering slashes", e.g. using an attribute @hover-slash.
If this attribute is not set, then it's up to the renderer to decide
how many beams/slashes are drawn on half notes.  For other durations
it's pretty much unambiguous anyway.  If it is set, then the number of
beams is @slash - @hover-slash.

Another question is whether we need to cover things like half notes
with two beams and one slash.  I didn't see that in the books.  I only
saw either a single beam with 0 or more slashes, or more beams and no
slashes.  If the answer is no, then a boolean attribute @hover-slash
could be used as well.  If not set, it's up to the renderer.  If it is
true, then there needs to be one beam and @slash - 1 hovering slashes
for half notes.  If false, there need to be "@slash" beams.  The
question is whether the attribute should have an effect if it's set on
notes with @dur != 2.

> Yet another possibility is to assume beaming based on the durations of the notes and count only "non-beam" slashes in @slash.

Maybe that's not so important because there's not much material using
<ftrem> yet, but that would be incompatible with the current practice,
right?

Thomas Weber