Class: HeadMusic::Style::Guidelines::PreferImperfect

Inherits:
Annotation
  • Object
show all
Defined in:
lib/head_music/style/guidelines/prefer_imperfect.rb

Overview

A counterpoint guideline

Constant Summary collapse

MESSAGE = 
"Prefer imperfect harmonic intervals."

Instance Method Summary collapse

Constructor Details

This class inherits a constructor from HeadMusic::Style::Annotation

Instance Method Details

#downbeat_harmonic_intervals_in_middle ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prefer_imperfect.rb', line 24

def downbeat_harmonic_intervals_in_middle
  downbeat_harmonic_intervals[1..-2]
end

#marks ⇒ Object 



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# File 'lib/head_music/style/guidelines/prefer_imperfect.rb', line 8

def marks
  HeadMusic::Style::Mark.for_all(perfect_intervals.map(&:notes).flatten) if ratio_of_perfect_intervals >= 0.5
end

#perfect_intervals ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prefer_imperfect.rb', line 20

def perfect_intervals
  downbeat_harmonic_intervals_in_middle.select { |interval| interval.perfect_consonance?(:two_part_harmony) }
end

#ratio_of_perfect_intervals ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prefer_imperfect.rb', line 14

def ratio_of_perfect_intervals
  return 0 if downbeat_harmonic_intervals_in_middle.nil?

  perfect_intervals.length.to_f / downbeat_harmonic_intervals.length
end