Re: Acciaccaturas and slashed stems

[David Kastrup]

Gilberto Agostinho <address@hidden> writes:

> First of all, thank you so much for doing this, I really appreciate it.
> Unfortunately I do not know how to apply the patch, but I created a small
> LilyPond code that could be used as a regression test:
>
> \version "2.17.26"
> {
>   \relative c'' {
>     \grace {a8 b } a1
>     \grace {a8 b c b gis } a1
>     \grace {a8 b c32 b c16 gis } a1
>     \grace {a8 b c16 d c4 b8 gis } a1
>     \grace {a8 b c16 d c4 b8 a b\fermata a16 gis } a1
>   }
> }
> {
>   \relative c'' {
>     \grace {a8[ b] } a1 
>     \grace {a8[ b c b gis] } a1 
>     \grace {a8[ b c32 b c16 gis] } a1
>     \grace {a8[ b c16 d] c4 b8[ gis] } a1
>     \grace {a8[ b c16 d] c4 b8 a b\fermata a16[ gis] } a1
>   }
> }
>
> On the top, you will see the graces behaving as they currently do
> (unbeamed). On the bottom you have the beamed ones. Please note that on the
> 5th example the last three eighth notes are supposed to be unbeamed, but I
> do not know how this will work after your patch (maybe it will need some
> command to break the automatic grace beaming).
>
> The logic behind my little examples above is to show:
> No. 1: simple beaming between 2 notes (simplest example)
> No. 2: simple beaming between more than 2 notes
> No. 3: beaming between notes of different values (but all shorter than a
> quarter note and thus having a flag that can be beamed)
> No. 4: beaming between notes of different values with a quarter note
> included in between (to show that the auto beam will still work properly)
> No. 5: a more complex example, where some notes are supposed to be unbeamed
> and some beamed.
>
> Please let me know if this is of any use.

The output will be as follows with the patch applied.

grace.pdf
Description: Adobe PDF document

You'll notice that automatic beaming starts at the beginning of the
phrase but not afterwards.  So more complex stuff still needs to be
beamed manually.  It would be possible to have every note be an
automatic beam starter, but then, say, the last measure would have been
rather cumbersome to type since you would need several \noBeam
statements.

So I think that this compromise is likely acceptable.  It will require
manual work in the last two measures to get the result you achieve
manually, but that's reasonably painless to do.  Having to slap a
\noBeam on every single note that should not be beamed seems excessive.

-- 
David Kastrup