Re: Impossible or ambiguous (de)crescendo in MIDI

[Cynthia Karl]

> Date: Wed, 02 Mar 2016 14:37:44 +0000
> From: Graham King <address@hidden>
> To: LilyPond Users <address@hidden>
> Subject: Impossible or ambiguous (de)crescendo in MIDI.
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset="us-ascii”
> 
<snip>

> 2) The second problem arose when I finally tracked down one such error.
> Here's the minimal example:
> 
>      \version "2.19.35"
> 
>      music = \relative {
>        c''2\p\< c |
>        c1\fz\>%-\omit\mf |
>        c\p  |
>      }
> 
>      \score {
>        \music
>      }
> 
>      \score {
>        \music
>        \midi {}
>      }
> 
> 
> As it stands, this gives two of these error messages.  

I think I understand why these errors are generated.  It would appear that \fz 
is not intended to be used as a dynamic - it is not mentioned in the NR.  
Nevertheless, is is defined as a dynamic script in the LP file 
dynamic-scripts-init.ly.  Unfortunately, there is no corresponding entry in 
midi.scm to assign a “factor of total volume” for this dynamic, without which 
the midi performer is unable to do anything sensible.

It is possible you might get the results you want by rewriting the snippet as:

>      music = \relative {
>        c''2\p\< c |
>        \tag #'pdf c1\fz\>
>        \tag #'midi c1\f->\>
>        c\p  |
>      }
> 
>      \score {
>        \keepWithTag #'pdf \music
>      }
> 
>      \score {
>        \keepWithTag #'midi \music
>        \midi {}
>      }
>