Re: Faulty extra beam with manual beam and cross-staff stems

[Ole V. Villumsen]

Hi Will,
Thanks for your question.

My first wish would be to have cross-staff stems explained in the NR proper, 
not just in a snippet. Maybe it would fit somewhere under 2.2.1 Common notation 
for keyboards? The description would obviously best make the requirements clear 
in the text, not only implicit from an example.

The snippet that you link to was one of the two examples I had also looked at. 
And yes, I had seen \autoBeamOff and \voiceOne in the Lilypond source, but 
their significance was not clear to me. Since the text preceding the snippet 
already states that the stem length needs not be specified, I would find it 
natural also to add the requirement that \autoBeamOff is needed.

Finally a warning message from Lilypond would be nice when I do it wrong so 
that I don’t start suspecting a bug. Explanatory and with suggestion how to fix 
if possible.

Cheers, Ole

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------- Original Message -------
On Tuesday, August 1st, 2023 at 22:15, William Rehwinkel 
<william@williamrehwinkel.net> wrote:

> I can see "\autoBeamOff" pretty clearly here, which was the first link found 
> from googling "lilypond cross-staff stems"
>
> https://lilypond.org/doc/v2.25/Documentation/snippets/staff-notation_003a-cross-staff-stems
>
> -will
>
> On 8/1/23 15:22, Ole V. Villumsen via bug-lilypond wrote:
>
>> Hi Jean,
>> indeed. I retract my bug report.
>> Your solution works in the case where I specify \crossStaff in the lower 
>> staff (or both) and, as you say, the manual beams only in the upper staff.
>> And no, this is pretty far from perfect and could also benefit from being 
>> made clear in the NR.
>> Cheers,
>> Ole
>>
>> Sent with Proton Mail secure email.
>>
>> ------- Original Message -------
>> On Tuesday, August 1st, 2023 at 20:46, Jean Abou Samra
>> [<jean@abou-samra.fr>](mailto:jean@abou-samra.fr)
>> wrote:
>>
>>> Le mardi 01 août 2023 à 18:34 +0000, Ole V. Villumsen via bug-lilypond a 
>>> écrit :
>>>
>>>> % Manual beams and cross-staff stems don’t seem to work together.
>>>> % Expected result: Shared stems across staves; beams above notes in upper 
>>>> staff only.
>>>>
>>>> % I have tried all possible combinations of specifying beams and 
>>>> \crossStaff in the
>>>> % upper staff, the lower one and both. I always get unwanted beams in the 
>>>> lower staff.
>>>
>>> You should add \autoBeamOff in the lower staff, and remove the manual beams 
>>> there.
>>>
>>> \version "2.25.7"
>>>
>>> \layout {
>>> \context {
>>> \PianoStaff
>>> \consists "Span_stem_engraver"
>>> }
>>> }
>>>
>>> \new PianoStaff <<
>>> \new Staff \relative {
>>> r8 e'[ e] r
>>> r e e r |
>>> r e[ e] r
>>> r e[ e] r |
>>> r e e r
>>> r e[ e] r |
>>> r e[ e] r
>>> r e e r |
>>> r e[ e] r
>>> r2 |
>>> }
>>> \new Staff \relative {
>>> \clef bass
>>> \stemUp
>>> \autoBeamOff
>>> \crossStaff {
>>> r8 g g r
>>> r g g r |
>>> r g g r
>>> r g g r |
>>> r g g r
>>> r g g r |
>>> r g g r
>>> r g g r |
>>> r g g r
>>> r2 |
>>> }
>>> }
>>>
>>> \crossStaff requires an explicit \autoBeamOff. I'm not saying that this is
>>> the perfect user interface, but there is no bug here.
>>>
>>> Jean
>
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