audio.rb

class Audio < ActiveRecord::Base
  def self.sync!
    [Audio::ProgramAudio, Audio::DirectAudio, Audio::EncoAudio].each do |klass|
      klass.sync!
    end
  end

  class EncoAudio < Audio
    def self.sync!
      AudioSyncher.new(foo, bar).sync_awaiting_audio_if_file_exists!
    end
  end

  class ProgramAudio < Audio
    def self.sync!
      # do other stuff
    end
  end

  class DirectAudio < Audio
    def self.sync!
      AudioSyncher.new(foo, bar).sync_awaiting_audio_if_file_exists!
    end
  end
  
  class UploadedAudio < Audio
    # no sync method
  end
  #
end

class AudioSyncher
  def initialize(foo, bar)
    ...
  end

  def sync_awaiting_audio_if_file_exists!
    ...
  end
end