Re: Pitch questions

[Han-Wen Nienhuys]

2007/10/10, Rune Zedeler <address@hidden>:
> void
> Pitch::transpose (Pitch delta)
> {
>    Rational new_alter = tone_pitch () + delta.tone_pitch ();
>
>    octave_ += delta.octave_;
>    notename_ += delta.notename_;
>    alteration_ += new_alter - tone_pitch ();
>
>    normalize ();
> }
>
> This looks very ineffecient.
>
>    Rational new_alter = tone_pitch () + delta.tone_pitch ();
>    alteration_ += new_alter - tone_pitch ();
>
> is equivalent to
>
> alteration_ += delta.tone_pitch ();

No it's not. tone_pitch() changes in between since notename_ is changed.
Think about: a major third on B is D#, so alteration is changed by an
amount that is
is not equal to the alteration of E-natural.

-- 
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen