Re: wrong beamlet direction in 6/8 and 3/4 measure for dotted quaver and semiquavers

[Carl Sorensen]

On 1/15/12 2:50 PM, "Martin Straeten" <address@hidden> wrote:

>> I'm not top posting.
>in 6/8 an 3/4 measure the beamlet of the last/first semiwaver
>points to the dotted quaver.
>
>semiquavers should be beamed together like in 2.14.2
>
>%-sample--
>\version "2.15.24"
>\score {
>\relative c'{
>       \time 6/8 
>       c16 d e f8.  c8. d16 e f
>       \time 3/4 
>       c16 d e f8.  c8. d16 e f
>}}

Having reviewed Gould on beaming, I don't believe that the 3/4 time
measure in this example shows a valid problem.

The rhythm in the 3/4 measure is an invalid measure.  The three beats in
the measure are combined in such a way that the beats are obscured,
falling in the middle of the two dotted quavers. (Did I use that term
correctly?)

To be a valid 3/4 rhythm, at least two out of the three beats should be
shown, according to Gould (page 168, top of page).  This rhythm shows only
one beat, the first.

Thus, the 3/4 rhythm could be

c16 d e f~f8 c8. d16 e f

Which shows beats one and two, or

c16 d e f8.c8~ c16 d e f

Which shows beats one and three.  Personally, I think the best is

c16 d e f~ f8 c~ c16 d e f

Which shows all three beats.  The beaming is appropriate for this rhythm.

I guess that beaming the three semiquavers together is the most attractive
option for the first two cases above.  But that implies a 6/8 accent
structure, rather than a 3/4 accent structure, so I think it's incorrect.

So at the moment, I believe the 6/8 beaming is a bug.  I believe the 3/4
beaming is more a misuse of lilypond, and there is no *right* beaming.

Thanks,

Carl