You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: voicing.rb
    path of file: ./repos/coltrane/lib/coltrane/theory
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Coltrane
  module Theory
    # This cl
    
      def initialize(*pitch_strings, pitches: nil)
        @pitches = begin
          if pitch_strings.any?
           pitch_strings.map { |s| Pitch[s] }
          elsif pitches
           pitches
          else
           raise WrongArgumentsError
          end