Re: Lilypond lobbying?

[David Kastrup]

Reinhold Kainhofer <address@hidden> writes:

> Am Friday, 26. August 2011, 12:48:28 schrieb Joseph Wakeling:
>> On 08/26/2011 10:28 AM, David Kastrup wrote:
>> > It's pretty much along the lines of the given verbal description.  You
>> > could also do something like
>> > 
>> > << c1 { s4\< s2\! s4 } >>
>> 
>> Is this a new notation for 2.14, or is it missing the \\ ?
>
> Neither. It simply means that the two music expressions ("c1" and the "<< ... 
>>>") are to be interpreted in parallel in the current context.
>
>> I ask because when compiling this under 2.12 I get two staves (see
>> attached).
>
> The cause here is once again our beloved implicit context
> creation... In the above case, no voice or staff has yet been created,
> the << does also not create one, so when lilypond sees the c1, it
> creates a voice+staff. When it then processes the s4\<, it does the
> same, because it is apparently not in the same voice (which was only
> created for the c1).

Using \skip instead of s probably would cure that, but ugh.  I think if
a note or "spacer rest" creates an implicit Voice context for the rest
of sequential music in { c ... } then it should do the same for << c
... >>.  Can anybody think of music where this would be a bad idea?  I
am not even convinced that
{ c d e f } { g h a b }
warrants two different contexts and consequently systems.  How do you
explain the output of

{ \transpose c g { c d e f }  g a b c' }

convincingly to anybody?

Or even

{ \transpose c g c d e f g a b c' }

How is one supposed to guess what happens here?

-- 
David Kastrup