Class: HeadMusic::Style::Guidelines::NoParallelPerfect

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

Overview

Base class for guidelines flagging parallel perfect consonances between consecutive harmonic intervals. Subclasses supply the set of harmonic intervals to analyze (e.g. downbeats or all syncopated positions).

Instance Method Summary collapse

Constructor Details

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

Instance Method Details

#analyzed_harmonic_intervals ⇒ Object (private)

Raises:

  • (NotImplementedError) 


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# File 'lib/head_music/style/guidelines/no_parallel_perfect.rb', line 16

def analyzed_harmonic_intervals
  raise NotImplementedError
end

#marks ⇒ Object 



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

def marks
  parallel_perfect_pairs.map do |pair|
    HeadMusic::Style::Mark.for_all(pair.flat_map(&:notes))
  end
end

#parallel_perfect_pairs ⇒ Object (private) 



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

def parallel_perfect_pairs
  analyzed_harmonic_intervals.each_cons(2).select do |first, second|
    first.perfect_consonance?(:two_part_harmony) &&
      second.perfect_consonance?(:two_part_harmony) &&
      same_simple_type?(first, second)
  end
end

#same_simple_type?(first, second) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/head_music/style/guidelines/no_parallel_perfect.rb', line 28

def same_simple_type?(first, second)
  first.simple_number == second.simple_number
end