Re: How to define a macros for writing predefined chords of arbitrary length?

[Thomas Morley]

2017-01-30 19:16 GMT+01:00 Mojca Miklavec <address@hidden>:
> Hi,
>
> I can easily use a macro to create chords of predefined lengths, say
>
>     chord_F = { <f a c'>4 }
>
> but the functionality is limited for what I want to achieve.
>
> On some instruments (like accordion) one gets that chord by pressing a
> single button and I need some reasonable way to enter them without
> messing everything up.
>
> (Some songs consist of only two different chords and I find it tedious
> to keep entering <f a c'> <e g c'> over and over again, making lots of
> mistakes, if I could assign that to just "F" and "C" or numbers 4 and
> 2. \somelongwordF and \somelongwordC are still better than writing out
> the full chord; the compiler would catch it if I make a spelling
> mistake.)
>
> What I would like to be able to do is:
>
> - specify lengths
>     \chord_F4 \chord_F2 or <\chord_F>4 <\chord_F>2
>
> - combine chords with other pitches (in theory perhaps with other
> chords as well, but I never needed that so far)
>     <f, \chord_F>8
>
>
> To get things like
>
>     chord_F = { f a c' }
>     melody = {
>         f,8 <\chord_F>8 c8 <\chord_F>8 |
>         <f, \chord_F>2
>     }
>
> What options do I have to achieve the desired functionality? (I don't
> care about the exact syntax as long as it would allow me to achieve
> consistency.)
>
>
> Thank you very much,
>     Mojca
>
> (Please CC me.)

How about:

\version "2.19.52"

chord =
#(define-music-function (mus dur)(ly:music? ly:duration?)
  (let ((evc-notes (extract-typed-music mus 'note-event)))
    (for-each
      (lambda (note-ev)
        (ly:music-set-property! note-ev 'duration dur))
      evc-notes)
    (make-event-chord evc-notes)))

chord_F = \chord <f a c'> \etc
chord_Gm = \chord <g' bes' d''> \etc


{
    \set Score.skipBars = ##t
    \chord_F16 \chord_F1 \chord_F32.. \chord_F\longa
    \chord_Gm128 \chord_Gm2 \chord_Gm4
    << f''8 \\ \repeat unfold 3 \chord_F16*2/3 >>
}


%% remark:
%% n.b.: \chord_F4 <-- a duration is needed, the value doesn't matter
chord_XY = \chord { fis'' \chord_F1 } \etc

{
    \chord_XY 64.
    \chord { gis'' \transpose f f' \chord_F4 ees } 32
}


The following I don't understand.
Not playing accordion, though

>
> PS: At some point in the future I would ideally like to be able to
> prepare single input to get both of the following modes as output (but
> that's already the next step):
>
>     \new Staff = "staff" <<
>       \new Voice = "bass" {
>         \clef bass
>         \repeat unfold 3 { f,8 <f a c'> c, <f a c'> | } % push mode
>         \repeat unfold 4 { g,8 <e g c'> c, <e g c'> | } % pull mode
>         <f, f a c'>2 | % push mode
>       }
>     >>
>
>     \new FiguredBass {
>       \figuremode {
>         \repeat unfold 3 { <4>8 <3> <2> <3> | } % push mode
>         \repeat unfold 4 { <2>8 <3> <4> <3> | } % pull mode
>         <4 3>2 | % push mode
>       }
>     }

Cheers,
  Harm