trying to create a note pattern using scheme ...

[Wilbert Berendsen]

Hi all,

this time I am really really delving into LilyPond, I am very much impressed 
with the notation quality of the recent versions. I am trying to set an organ 
piece with many repetitive notes in it, and to get a grasp on the underlying 
structure of Lilypond.

Many measures have note patterns like this one:

e8 g16 e g8 e g16 e g8 e g

so, two notes or chords played alternatively with the rhythm |8 16 16 8 | 8 16 
16 8 | 8 8 | (in time 8/8).

What would be an efficient way to create those patterns using a scheme 
function, so that I could write:

        \pat a c

or:

        \pat <a e> <c g>

I am fiddling with the example from the manual[1]:

pattern = #(define-music-function (parser location x y) (ly:music? ly:music?)
     #{
       $x e8 a b $y b a e
     #})

but when I try to add or change a duration (like $x 8 $y 16 etc.) I get syntax 
errors, so probably I must try to build the lilypond music expression fully 
from within scheme?

Is there anyone with some experience on this who could point me in the correct 
direction?

[1] 
http://www.lilypond.org/doc/v2.11/Documentation/user/lilypond/Advanced-tweaks-with-Scheme

Thanks for this wonderful Free music notation software,
best regards,
Wilbert Berendsen

-- 
http://www.wilbertberendsen.nl/
"You must be the change you wish to see in the world."
        -- Mahatma Gandi