Re: Issue 795 in lilypond: Beams do not take grace notes into account

[address@hidden]

On Apr 2, 2011, at 8:08 PM, Colin Campbell wrote:

> On 11-04-02 05:18 PM, address@hidden wrote:
>> 
>> Comment #5 on issue 795 by address@hidden: Beams do not take grace notes 
>> into account
>> http://code.google.com/p/lilypond/issues/detail?id=795
>> 
>> Hey Colin,
>> 
>> I'm not sure if this is a problem - the stem is just covered by the stem of 
>> the 8th note.  One can imagine that if the regtest had set the 8th notes 
>> lower, the quarter note stem would be subsumed into the 8th note stem.  ie:
>> 
>> quoteMe = \relative c' { fis4 r16  a8.-> b4-\ff c }
>> 
>> \addQuote quoteMe \quoteMe
>> original = \relative c'' { c8 d s2 \stemDown a8 fis8 }
>> 
>> <<
>>    \new Staff {
>>        \set Staff.instrumentName = "quoteMe"
>>        \quoteMe
>>    }
>>    \new Staff {
>>        \set Staff.instrumentName = "orig"
>>        \original
>>    }
>>    \new Staff \relative c'' <<
>> 
>>        \set Staff.instrumentName = "orig+quote"
>>        \set Staff.quotedEventTypes = #'(note-event articulation-event)
>>        \original
>>        { s4 \quoteDuring #"quoteMe" { s2. } }
>> >>
>> 
>> 
>> I think this addresses a larger issue, however, of being able to turn on and 
>> off certain grobs in the beam-collision-engraver.  This is doable via a 
>> modifiable property (ie Beam #'avoid = #'(stem beam note-head clef 
>> time-signature)), but that seems like it'd be appropriate for a separate 
>> patch.
>> 
> 
> I'm afraid I'm looking at it from a rather unsophisticated view, Mike: the 
> original showed reasonably clearly that there was a quarter note sharing a 
> head with one of the eighths, the patched version, by lengthening the stem of 
> the beamed notes, hides the quarter note completely. An amateur bass singer 
> such as I would not know it was there.
> 
> Colin
> 

I definitely see what you're saying.  My point above was not that the 
disappearing stem was a good (or bad) thing, but rather that in other 
circumstances (like the snippet I give above), the stem disappears even without 
the new patch. The protrusion of the quarter not stem is not a feature of 
quote-me but rather a product of happenstance.  The attached example, made 
without the proposed patch, provides another instance of the quarter note stem 
being gobbled up by the 8th note stem.

In your amateur choir scenario, in order to follow the bass line, it would be 
necessary that the two voices be typeset with stems in opposite directions.  
Otherwise, it is impossible to know who is singing what.

It's for this reason that I'm not averse to this change in the regtest.

Cheers,
MS

PastedGraphic-1.pdf
Description: Adobe PDF document