Class: HeadMusic::Content::CantusFirmus::Example

Inherits:
Object
  • Object
show all
Defined in:
lib/head_music/content/cantus_firmus/example.rb

Overview

Sample cantus firmus examples from various pedagogical sources. These are traditional melodies used for teaching counterpoint.

Constant Summary collapse

EXAMPLES_DATA = 
YAML.load_file(File.expand_path("examples.yml", __dir__)).freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data:) ⇒ Example

Returns a new instance of Example.



39
40
41
42
43
44
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 39

def initialize(data:)
  @source = Source.get(data["source"])
  @tonal_center = data["tonal_center"]
  @mode = data["mode"]&.to_sym
  @pitches = data["pitches"] || []
end

Instance Attribute Details

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



9
10
11
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 9

def mode
  @mode
end

#pitches ⇒ Object (readonly)

Returns the value of attribute pitches.



9
10
11
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 9

def pitches
  @pitches
end

#source ⇒ Object (readonly)

Returns the value of attribute source.



9
10
11
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 9

def source
  @source
end

#tonal_center ⇒ Object (readonly)

Returns the value of attribute tonal_center.



9
10
11
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 9

def tonal_center
  @tonal_center
end

Class Method Details

.all ⇒ Object 



12
13
14
15
16
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 12

def all
  @all ||= EXAMPLES_DATA["cantus_firmus_examples"].map do |data|
    new(data: data)
  end
end

.by_mode(mode_name) ⇒ Object 



29
30
31
32
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 29

def by_mode(mode_name)
  normalized_mode = mode_name.to_s.downcase
  all.select { |example| example.mode.to_s.downcase == normalized_mode }
end

.by_source(source_identifier) ⇒ Object 



18
19
20
21
22
23
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 18

def by_source(source_identifier)
  source = Source.get(source_identifier)
  return [] unless source

  all.select { |example| example.source == source }
end

.by_tonal_center(tonal_center_name) ⇒ Object 



34
35
36
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 34

def by_tonal_center(tonal_center_name)
  all.select { |example| example.tonal_center.to_s == tonal_center_name.to_s }
end

.sources ⇒ Object 



25
26
27
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 25

def sources
  all.map(&:source).uniq
end

Instance Method Details

#length ⇒ Object 



46
47
48
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 46

def length
  pitches.length
end

#to_s ⇒ Object 



50
51
52
 
# File 'lib/head_music/content/cantus_firmus/example.rb', line 50

def to_s
  "#{tonal_center} #{mode} (#{source})"
end