Class: HeadMusic::Style::Guides::SpeciesMelody

Inherits:
Base
  • Object
show all
Defined in:
lib/head_music/style/guides/species_melody.rb

Overview

Base class for species melody guides. Inherits analysis behavior from Base; exists as a semantic marker distinguishing melody guides from harmony guides.

Constant Summary collapse

MELODIC_GATES =

Three notes is where a contour becomes possible at all.

Splatted by each subclass rather than declared here: declarations are a per-class ivar, so gate_items here would leave every subclass ungated, and normalize would not object because the subclasses have primaries.

[
  HeadMusic::Style::Guidelines::MinimumNotes.with(3)
].freeze
MELODIC_CORE = 
[
  HeadMusic::Style::Guidelines::ConsonantClimax,
  HeadMusic::Style::Guidelines::Diatonic,
  HeadMusic::Style::Guidelines::LimitOctaveLeaps,
  HeadMusic::Style::Guidelines::MostlyConjunct,
  HeadMusic::Style::Guidelines::SingableIntervals,
  HeadMusic::Style::Guidelines::SingableRange
].freeze
MOVING_MELODIC_CORE =

For the moving species (second through fifth), whose melodies progress within the bar rather than holding a whole note.

Two of these read as harmonic rules and neither moves to the harmonic cores. StartOnPerfectConsonance is not harmonic despite its name – it measures the interval from the key’s tonic, not from the companion voice, so it scores a solo voice legitimately. StepOutOfUnison genuinely is harmonic and does score a free 1.0 for a solo voice, but that free-1.0 belongs to the identification problem rather than to a weighting question, and moving it costs six assertions across the melody specs to buy 0.007 of one harmony grade.

[
  HeadMusic::Style::Guidelines::AlwaysMove,
  HeadMusic::Style::Guidelines::EndOnTonic,
  HeadMusic::Style::Guidelines::FrequentDirectionChanges,
  HeadMusic::Style::Guidelines::NoRestsAfterNote,
  HeadMusic::Style::Guidelines::NoteFillsFinalBar,
  HeadMusic::Style::Guidelines::PrepareOctaveLeaps,
  HeadMusic::Style::Guidelines::StartOnPerfectConsonance,
  HeadMusic::Style::Guidelines::StepOutOfUnison,
  HeadMusic::Style::Guidelines::StepUpToFinalNote
].freeze
MOVING_MELODIC_CRAFT =

What a moving species inherits: both cores, splatted into one secondary_items call. The two guides that hold a whole note per bar – FirstSpeciesMelody and FirstThreeSpeciesMelody – name their background by hand instead, because each wants a different subset of MOVING_MELODIC_CORE.

[*MELODIC_CORE, *MOVING_MELODIC_CORE].freeze

Class Method Summary collapse

Class Method Details

.category ⇒ Object 



53
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# File 'lib/head_music/style/guides/species_melody.rb', line 53

def self.category
  :melody
end