Re: [Best Practices] instrument changes

[Gilles Sadowski]

Hi.

> >
> > I would love to put together a "Best Practices" example/snippet/document
> 
> Good idea!
> I don't write much music for transposing instruments, so i cannot give
> any advice, but i have a question that may trigger a discussion: how
> to prepare scores with transposing instruments so that they are
> structurally correct? Consider this canon:
> 
> common = {
>   \key e \minor
>   \time 4/4
> }
> melody = \relative c' {
>   e4 d8 fis e4 b |
>   e8 e fis fis g a16[ g] fis4 |
>   b8 b a a g a16 g fis8 b, |
>   e4 d8 fis e2
> }
> <<
>   \new Staff = violin { \common \melody R1 }
>   \new Staff = "clarinet in A" \transpose a c' { \common R1 \melody }
> >>
> 
> If i understand how transposing instruments should be notated, the
> output is how it should look like from a performer's point of view.
> However, it is structurally wrong: for example MIDI output will be
> bad, because internally the two parts have differently pitched
> melodies (while they should be pitched the same and only displayed
> differently).
> What is the correct way of doing this?

Something along those lines:

If the source contains notes in concert pitch:
---CUT---
   \new Staff = "clarinet in A" {
     \transposition a {
       \transpose c a {
         <<
           \common
           \melody
         >>
       }
     }
   }
---CUT---

If the source contains notes written for the instrument in A: 
---CUT---
  \new Staff = "clarinet in A" {
    \transposition a {
      \transpose c a {
        <<
          \common
          \transpose a c {
            \melody
          }
        >>
      }
    }
  }
---CUT---

Best,
Gilles