Re: Two issue with Measure_grouping_engraver

[Thomas Morley]

2018-08-07 12:23 GMT+02:00 James Lowe <address@hidden>:

>> timeSignatureFraction: (4 . 8)
>>      beatStructure: (2 2)
>>      baseMoment: #<Mom 1/8>
>>            beamExceptions: ()

>>

> I have on supplementary based on what you have said.
>
> If you look at one of the original examples (I'll attach it here as well),
> you can see engravings for 'single' notes (which may not be the same as
> 'beats' hence my supplementary.

Indeed, in 4/8 the beat (baseMoment) is 1/8 not 1/4

> This is 4/8 time but the notes are crotchets (i.e. 4 not 8) so is this
> effectively '2' beats in this context ?

True as well, beatStructure in 4/8 is '(2 2)

So below works as expected:

\new Staff \with { \consists "Measure_grouping_engraver" }
{
  \time 4/8
  a'4 4
}


Though, there is another not yet mentioned point.
MeasureGrouping also relies on the actual music rhythmically matching
the beatStructure.

\new Staff \with { \consists "Measure_grouping_engraver" }
{
  \time 4/8
  a'2
}
Will print only one bracket.

To get two brackets a second voice could be inserted, easily:
\new Staff \with { \consists "Measure_grouping_engraver" }
<<
    { \time 4/8 a'2 }
    { s4 s }
>>

No bug I'd say, but likely worth explaining.


Though, why is the a first bracket printed, even if no music
rhythmically matches the beatStructure?
See 3rd measure of:

\new Staff \with { \consists "Measure_grouping_engraver" }
{
  \time 4/8
  a'4 4
  a'2*7/4 a'8
  |
}

That I can't explain.
Others?


Cheers,
  Harm