Re: irrational meters

[Karim Haddad]

Thank you a lot Leo for your advice.
I'll hence stick with solution #1 which looks preferable.

@all
Now about "irrational meter" (or "irrational" rhythms), well this denomination 
is from the fifties. I am aware that mathematically this is not correct since 
it is a fraction.However, "irregular" is somehow more vague and doesn't relate 
to anything in particular. Thanks to Hans' link that shows that it is a somehow 
a common terminology in music practice. 

Best to all of you, and thank you for all your comments.

Karim



On Tue, Jan 17, 2023 at 01:30:49PM +0100, Leo Correia de Verdier wrote:
> Hi Karim!
> 
> Your first example seems to work to me (I don’t do irrational meters 
> everyday, so there might be something I’m missing. I would probably write the 
> tuplets explicitly rather than use \scaleDurations). 
> \set Staff.timeSignatureFraction is superfluous, the time signature already 
> does that.
> 
> I’m not sure what you’re aiming at with the second example. One source of 
> error is that you have quoted ly:make-moment, and it wants its arguments as 
> elements of a list, not as a fraction, so: 
> #(ly:make-moment 16 25)
> , not
> #'(ly:make-moment 16/25)
> But it is still not the right amount of notes in the bar.
> 
> HTH
> /Leo
> 
> > 17 jan. 2023 kl. 12:16 skrev Karim Haddad <karim.haddad@ircam.fr>:
> > 
> > Hi,
> > 
> > I am wondering which is the best way to write irrational meters (with tempo 
> > modulations)
> > 
> > 1)
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > \version "2.24.0"
> > \score {
> > {
> > 
> > \clef "G"
> > 
> > \scaleDurations 4/5 {
> > \time 4/5
> > \set Staff.timeSignatureFraction = #'(4 . 5)
> > \mark \markup {\left-column {{\line { \smaller \general-align #Y #DOWN  
> > \note {4} #1 " = 60 "}} \tiny "1"}}
> > c'4
> > c'4
> > c'4
> > c'4
> > |
> > }
> > \once \set Staff.whichBar = "|"
> > }
> > 
> > 
> > \layout {
> > 
> > \context {\Score
> >     %    measureBarType=#""
> >              }
> > 
> > }
> > }
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > 
> > or
> > 
> > 2)
> > 
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > \version "2.24.0"
> > \score {
> > {
> > \clef "G"
> > 
> > \time 4/5
> > \set Staff.timeSignatureFraction = #'(4 . 5)
> > \set Timing.measureLength = #'(ly:make-moment 16/25)
> > \mark \markup {\left-column {{\line { \smaller \general-align #Y #DOWN  
> > \note {4} #1 " = 60 "}} \tiny "1"}}
> > c'4
> > c'4
> > c'4
> > c'4
> > |
> > \once \set Staff.whichBar = "|"
> > }
> > 
> > \layout {
> > 
> > \context {\Score
> >         measureBarType=#""
> >               }
> > 
> > }
> > }
> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > 
> > 
> > Now the first solution outputs:
> > 
> > Processing `irr1.ly'
> > Parsing...
> > Interpreting music...
> > irr1.ly:13:1: warning: strange time signature found: 4/5
> > 
> > \time 4/5
> > Preprocessing graphical objects...
> > 
> > 
> > Which looks good to me as a warning
> > 
> > However, the second solution gives:
> > 
> > Processing `irr2.ly'
> > Parsing...
> > Interpreting music...
> > warning: type check for `measureLength' failed; value `(ly:make-moment 
> > 16/25)' must be of type `moment'
> > irr2.ly:12:1: warning: strange time signature found: 4/5
> > 
> > \time 4/5
> > irr2.ly:20:1: warning: barcheck failed at: 1/5
> > 
> > |
> > Preprocessing graphical objects...
> > 
> > 
> > And if we comment measureBarType=#"" we will have a strange bar at the end.
> > 
> > 
> > Best Regards
> > 
> > 
> > -- 
> > Karim Haddad
> > 
> > Music Representations Team, IRCAM
> > Research and development manager.
> > 
> > 
> 

-- 
Karim Haddad

Music Representations Team, IRCAM
Research and development manager.