lib/head_music/pitch.rb in head_music-0.22.0 vs lib/head_music/pitch.rb in head_music-0.23.0

@@ -62,11 +62,12 @@
     fetch_or_create(spelling, natural_letter_pitch.octave)
   end
 
   def self.natural_letter_pitch(number, letter_name)
     natural_letter_pitch = get(HeadMusic::LetterName.get(letter_name).pitch_class)
-    natural_letter_pitch += 12 while (number - natural_letter_pitch.to_i).to_i >= 11
+    natural_letter_pitch += 12 while (number.to_i - natural_letter_pitch.to_i) >= 6
+    natural_letter_pitch -= 12 while (number.to_i - natural_letter_pitch.to_i) <= -6
     get(natural_letter_pitch)
   end
 
   def self.fetch_or_create(spelling, octave = nil)
     octave ||= HeadMusic::Octave::DEFAULT
@@ -104,25 +105,25 @@
   def natural
     HeadMusic::Pitch.get(to_s.gsub(HeadMusic::Sign.matcher, ''))
   end
 
   def +(other)
-    if other.is_a?(HeadMusic::FunctionalInterval)
+    if other.is_a?(HeadMusic::DiatonicInterval)
       # return a pitch
       other.above(self)
     else
       # assume value represents an interval in semitones and return another pitch
       HeadMusic::Pitch.get(to_i + other.to_i)
     end
   end
 
   def -(other)
-    if other.is_a?(HeadMusic::FunctionalInterval)
+    if other.is_a?(HeadMusic::DiatonicInterval)
       # return a pitch
       other.below(self)
     elsif other.is_a?(HeadMusic::Pitch)
       # return an interval
-      HeadMusic::Interval.get(to_i - other.to_i)
+      HeadMusic::ChromaticInterval.get(to_i - other.to_i)
     else
       # assume value represents an interval in semitones and return another pitch
       HeadMusic::Pitch.get(to_i - other.to_i)
     end
   end