Re: Frescobaldi 0.7.6 released

[Trevor Daniels]

Wilbert Berendsen wrote Thursday, February 26, 2009 9:21 AM
> Op woensdag 25 februari 2009, schreef Stefan Thomas:
> > I'm only missing a feature, that can change pitches 
> > enharmonically,
> > e.g. convert a cis to des.
> > Is it possible to write a plugin for this?
>
> Yes, this kind of operations is planned, but there is one hairy 
> detail:
> changing the base step can cause the relative distances to work 
> out different
> (e.g. in relative mode, c fis goes up, but c ges goes down, but 
> also in
> absolute mode enharmonic changes can alter the octave a note is 
> in, e.g.:
> b -> ces).

You've probably realised that you can't determine whether
the next note in relative mode goes up or down by counting
the relative distance between them.  For example:

the fis in \relative c' { ces fis } goes up (7 semitones)

but in \relative c' { b fis } it goes down (same interval)

also in \relative c' { bisis feses }(2 semitones) the feses
actually goes down!

That is because the accidentals are totally ignored in
determining whether the following note goes up or down,
and the distance between them is then determined by
counting staff spaces.  Whichever direction is 3 or less
is taken.

So for {ces fis} think of {c f} - 3 staff spaces up,
4 down, so direction is up

for {b fis} think of {b f} - 4 staff spaces up,
3 down, so direction is down

and for {bisis feses} think of {b f} - 4 staff spaces
up and 3 down, so direction is down.

Apologies if you are already well aware of this.

Trevor