Class: Musa::Scales::BluesScaleKind

Inherits:

ScaleKind

• Object
• ScaleKind
• Musa::Scales::BluesScaleKind

Defined in:

lib/musa-dsl/music/scale_kinds/blues/blues_scale_kind.rb

Overview

Blues scale kind (minor blues).

BluesScaleKind defines the blues scale, a six-note scale that adds the "blue note" (b5) to the minor pentatonic scale. This is the quintessential scale for blues, rock, and jazz improvisation.

Pitch Structure

6 degrees plus extended:

Scale Degrees (lowercase for minor quality):

• i (tonic): Root (0 semitones)
• iii (mediant): Minor third (3 semitones)
• iv (subdominant): Perfect fourth (5 semitones)
• blue (blue note): Diminished fifth (6 semitones) ← CHARACTERISTIC
• v (dominant): Perfect fifth (7 semitones)
• vii (subtonic): Minor seventh (10 semitones)

The Blue Note

The b5 (diminished fifth) is the defining characteristic of the blues scale. It creates tension that resolves either up to the 5th or down to the 4th, giving the scale its distinctive "bluesy" sound.

Musical Character

The blues scale:

• Foundation of blues improvisation
• Works over minor, dominant 7th, and even major chords
• The blue note adds expressive tension
• Common in blues, rock, jazz, and funk

Usage

a_blues = Scales[:et12][440.0][:blues][69]
a_blues.tonic  # A (69)
a_blues.blue   # Eb (75) - the blue note

See Also:

• Abstract base class
• Minor pentatonic (without blue note)
• Major blues scale

Constant Summary

@@pitches =

[{ functions: %i[i _1 tonic first],
pitch: 0 },
             { functions: %i[iii _2 mediant second],
pitch: 3 },
             { functions: %i[iv _3 subdominant third],
pitch: 5 },
             { functions: %i[blue _4 fourth],
pitch: 6 },
             { functions: %i[v _5 dominant fifth],
pitch: 7 },
             { functions: %i[vii _6 subtonic sixth],
pitch: 10 },
             { functions: %i[viii _7 seventh],
pitch: 12 },
             { functions: %i[x _8 eighth],
pitch: 12 + 3 },
             { functions: %i[xi _9 ninth],
pitch: 12 + 5 },
             { functions: %i[blue2 _10 tenth],
pitch: 12 + 6 },
             { functions: %i[xii _11 eleventh],
pitch: 12 + 7 },
             { functions: %i[xiv _12 twelfth],
pitch: 12 + 10 }].freeze

Class Method Summary

• .grades ⇒ Object
• .id ⇒ Object
• .pitches ⇒ Object

Constructor Details

This class inherits a constructor from Musa::Scales::ScaleKind

Class Method Details

.grades ⇒ Object

# File 'lib/musa-dsl/music/scale_kinds/blues/blues_scale_kind.rb', line 87

def grades
  6
end

.id ⇒ Object

# File 'lib/musa-dsl/music/scale_kinds/blues/blues_scale_kind.rb', line 91

def id
  :blues
end

.pitches ⇒ Object

# File 'lib/musa-dsl/music/scale_kinds/blues/blues_scale_kind.rb', line 83

def pitches
  @@pitches
end