Re: Bug? a minimal example to show "going back in midi time"

[Carl Sorensen]

On 7/9/10 5:03 PM, "胡海鹏 - Hu Haipeng" <address@hidden> wrote:

> Dear All,
>   After reading the messages about "going back in midi time", I realized that
> the main problem of my overture's midi output is not totally because of
> articulate. Here's the small intro containing just 8 bars, and the problem is
> at bar 7. Please run it, and you'll see these warnings. I add many c's in harp
> part, and you will hear bad time delay in other instruments at the beginning
> of bar 8. Serious bug, and if you acknowledge, I'll forward it to bug list.
> Or, must I change all graces into tuplets or vice versa in the tag midi parts?

So the challenge we have here is that in the printed music, grace notes take
up no musical time.

But in midi they do (otherwise we wouldn't hear them).

So for the midi, you must figure out what you want the graces to sound like,
and write the music so it takes up the same amount of time as in the
parallel voices.  You can't just use \grace to do that.

Here's a simple example that avoids the error:

musicOne = \relative c'' {
  \tag #'print {
     \grace {a16 a}
     c4 c c c
  }
  \tag #'midi {
    a16 a
    c4*1/2 c4 c c
  }
}

\score {
  <<
    \new Staff {
     \keepWithTag #'print \musicOne
    }

    \new Staff {
      \relative c'' {
        a4 a a a
        }
    }
  >>
  \layout{}
}

\score {
  <<
    \new Staff {
      \keepWithTag #'midi \musicOne
   }

   \new Staff {
     \relative c'' {
       a4 a a a
     }
   }
 >>
 \midi{}
}



HTH,

Carl