trill & midi

[Gianmaria Lari]

I would like to change the trill speed in the midi output. I tried to change the "#(define..." like in the following code but without success. Any suggestion?

\version "2.19.81"

\include "articulate.ly"

#(define ac:maxTwiddleTime (ly:make-moment 1/240))

\score {

  \articulate {\time 2/4 c'2 \trill}

  \layout {}

  \midi {}

}

Thank you, g.