Re: Persian musical koron and sori

[Hans Aberg]

On 16 Feb 2009, at 23:14, Kees van den Doel wrote:

> > > E.g., D Ep F (F 20 cent flat, so actually D Ep and Ep F are
> > the same
> > > interval)
> >
> > If the musical function or intent is that these intervals should
> > be
> > equal, then the note is F#pp, that is, a double koron.
>
> Cute, I never thought of that! However it does't quite work because   
> the *approximate* 20C fat
> is independent of the koron (which is *approximately* 40C).  So the  
> equation
> '>' = "#p' is an exact constraint.

That is why I mentioned musical function: if it is that D Ep and Ep F- 
lowered should always be equal, then the note will always be F#pp,  
regardless what the koron is set to.

If one the other hand, it is just lowered an indefinite amount for  
stylistic reason not attempting to achieve equality of these  
intervals, then it is a different musical function, resulting in the  
pair independent of the koron-sori one, resulting in a new  
intermediate pith relative to the diatonic notation system (regardless  
whether you want top print them or not in the score).

> Anyways the 20C flat note is not considered an accidental, not  
> notated, inconsistently used, and
> irrelevant for notation.

> > On the other hand, if it is lowered an unspecified amount, then
> > when
> > transposed, you will need another symbol that raises an interval
> > so
> > that the sum is M-m.
>
> If you look at the persian.ly file I sent, you will find the symbol  
> for that I think (a blank).

So it means that you have two notational symbols, both printed as a  
blank: in a transposed situation, you may have to use the other. It is  
not very intuitive - so even though it is not explicitly notated, it  
might be good to be able to do so.

  Hans