Re: Default beaming for 3/4

[David Kastrup]

"Phil Holmes" <address@hidden> writes:

> ----- Original Message ----- 
> From: "David Kastrup" <address@hidden>
> To: <address@hidden>
> Sent: Friday, August 26, 2011 1:23 PM
> Subject: Re: Default beaming for 3/4
>
>
>> Nick Payne <address@hidden> writes:
>>
>>> According to Gould (p.153, about half way down the page), the Lilypond
>>> default beaming for 3/4 is incorrect in the following example; it
>>> should be beamed as in the second bar:
>>>
>>> \version "2.14.2"
>>>
>>> \relative c' {
>>>     \time 3/4
>>>     c4. c8 c c
>>>     c4. c8 c[ c]
>>> }
>>
>> Is that the _exact_ example given by Gould?
>
> Yes.

Sigh.  That makes it harder to find good rules.  For example, consider
\relative c' {
  \time 3/4
     c8 c c c c c
      r c c c c c
}
How would you want that beamed?  Now

\relative c' {
  \time 3/4
     c8 c c c c c
      r4 r8 c c c
}

And then
\relative c' {
  \time 3/4
     c8 c c c c c
     r4. c8 c c
}

And finally again
\relative c' {
  \time 3/4
   c4~ c8 c c c
}

and
\relative c' {
  \time 3/4
  c4. c8 c c c
}

My personal leaning is towards not giving the off-beat a stem of its own
if the on-beat has been merged into another note or rest.  So my
personal feeling is to beam like in the second system:

\new StaffGroup <<
  \time 3/4
  \relative c' {
    c8 c c c c c
    r c c c c c
    r4 r8 c c c
    r4. c8 c c
    c4~ c8 c c c
    c4. c8 c c
  }
  \relative c' {
    c8[ c c c c c]
    r c[ c c c c]
    r4 r8 c c[ c]
    r4. c8[ c c]
    c4~ c8 c c[ c]
    c4. c8[ c c]
  }
>>

Note that this would not agree with Gould.  Paraphrasing the gut rule I
apply here, this would likely be something like

  An off-beat can be beamed to the next group if its on-beat is not
  explicitly present.

Gould-compatible would be something like

  Rests, spacer rests and notes implicit in augmentation dots are
  counted as normal notes in an autobeamed figure with regard to
  deciding whether a beaming exception is to be applied.  Note that the
  autobeam will in no case actually extend across a rest.

That would split the beams of the last measure, but retain those of the
second measure.

-- 
David Kastrup