Re: Transposing instruments

[Helge Kruse]

Am 07.06.2012 17:23, schrieb Gilles Sadowski:
> > besides some other voices. I know the name "Clarinet in B" but
>
> Likely, this should have been "Clarinet in Bb" where the small "b" is for
> "flat" (i.e. a clarinet in B flat, where a "c" on the clarinet will sound
> as "b flat" in concert pitch).

You're right. It's designated with "Klarinette in B" what is "Clarinet 
in Bb". That's my mistake.

> Assuming that "clarinetNotes" contains the notes:
> If the part contains the notes in _concert_ pitch, you use the:
>
>       \transposition bes {% make MIDI sound right
>         \transpose bes c { % transpose to clarinet notation
>           <<
>             \global
>             \clarinetNotes
>           >>
>        }
>      }
>
>
> If the part contains the notes as transposed for clarinet, you use:
>
>      \transposition bes { % make MIDI sound right
>        \transpose bes c { % transpose to clarinet notation
>           <<
>             \global
>             \transpose c bes { % transpose to concert pitch
>              \clarinetNotes
>             }
>           >>
>         }
>       }
>     }
>
> and the MIDI will sound OK while the PDF will show the part transposed for
> clarinet.
> [In the above, "\global" contains e.g. the actual "\key" (i.e. in concert
> pitch). For example, if the piece is in G minor, the part for clarinet in Bb
> will be written in A minor.]

With Davids' hint I found a way to do this with much less coding. I 
write the score as it should look in the score (A minor). When I add the 
\transposition I get for the sample below following MIDI output:
Oboe: d, Clarinet: bes, French horn: g

oboe      = \relative c'' { \key g \minor      d16 d8. ~ d4 }
clarinetB = \relative c'' { \transposition bes c16 c8. ~ c4 }
hornF     = \relative c'' { \transposition f   d16 d8. ~ d4 }

\score
{
  <<
    \new Staff \with { midiInstrument="oboe"        } { \oboe }
    \new Staff \with { midiInstrument="clarinet"    } { \clarinetB }
    \new Staff \with { midiInstrument="french horn" } { \hornF }
  >>
  \layout {}
  \midi {}
}

I think this is straight forward as the \transposition affects the MIDI 
output only. And: it's well documented, I must admit.
http://www.lilypond.org/doc/v2.15/Documentation/notation/displaying-pitches#instrument-transpositions

Regards
Helge