On Sep 29, 3:56 pm, "D'Arcy J.M. Cain" <[EMAIL PROTECTED]> wrote: > On Mon, 29 Sep 2008 20:29:44 +0200 > > "Mr.SpOOn" <[EMAIL PROTECTED]> wrote: > > > Couldn't the note class simply have a list of all the notes and have a > > > simple method calculate the actual pitch? > > > That's not really how it works. There exists just 12 octave > > independent pitch classes. This means that there is a pitch class C > > with all possible Cs. There ambiguities with accidentals, because > > different named notes fall in the same pitch class. The difference is > > important for the musical theory, because C# and Db belongs to the > > same pitch class (actually they are the same note, they sounds > > completely identical -- because on the piano you play them pressing > > the same key), but in a scale they have a very different role. > > Sure, they are enharmonically identical but in our tempered scale. > That's why my example showed it as (note, octave, accidental) rather > than a specific note. It would differentiate between these. > > > For example, the interval C F# is an "augmented fourth", because what > > really matters are the natural note (C and F), and their distance if > > 4. Then it is augmented due to the #- > > > But the interval C Gb (Gb is the same as F#) is a "diminished fifth". > > This is true. My simple example would not have dealt with this. The > arguments would have to be the full tuple rather than the actual pitch. > > > So I can't list all pitches. > > You can but you can't store them as raw pitches. > > > > def interval(self, lower, higher) > > > if lower > higher: > > > # uncomment one of the two following lines depending > > > # on the behaviour you want > > > #lower,higher = higher,lower > > > #higher += 12 > > > > # could use some error trapping > > > return self.interval_name[higher - lower] > > > > Note that lower and higher could be a note object that you have to > > > convert to integers first. > > > I can't estabilish which note is higher, because all the analysis part > > is octave independent. Anyway thanks for the ideas. > > I'm not sure I understand this. You either have to assume that the > first note is the root or the lower one is. What other options are > there? It sounds like your requirement is "higher += 12" or some > variant. It also depends on whether you need to deal with things like > ninths and thirteenths. > > Anyway, I was just tossing out ideas. You know what your requirements > are better than I. > > -- > D'Arcy J.M. Cain <[EMAIL PROTECTED]> | Democracy is three > wolveshttp://www.druid.net/darcy/ | and a sheep voting on > +1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
I like D'Arcy's tuples so far. You could have a 4th element that contains adjustment for temper. Octave could be None. You want ( 4, None, 1 ) "sharp 4th" == ( 5, None, -1 ) "flat 5th", but you can't have it. The closest ones are Note( 4, None, 1 )== Note( 5, None, -1 ) or Note(4, None, 1 ).enh_cmp( Note( 5, None, -1 ) ). More elaborate code means more options for calling, though: Note(4, None, 1 ).cmp_enh( 5, None, -1 ), and just call the constructor on the 3 arguments. You also want Note( 9, None, 0 ).cmp_octave( 2, Rel+ 1, 0 ), 9th== 2nd + 1 octave, and Note( 9, None, 0 ).cmp_nooctave( 2, None, 0 ), where cmp_... functions return in ( -1, 0, 1 ), and the middle term can be a class Relative instance, which indicates a relative octave instead of absolute... or just start at 4. -- http://mail.python.org/mailman/listinfo/python-list
