class KaraokeSong < Song 
  # Format ourselves as a string by appending 
  # our lyrics to our parent's #to_s value. 
  def to_s 
    super + " [#{@lyrics}]" 
  end 
end 
aSong = KaraokeSong.new("My Way", "Sinatra", 225, "And now, the...") 
aSong.to_s

class Piece                                   # Define the Piece class.
    def initialize (name, composer, duration)  # Define initialize method, which is what parameters will get passed to
      @piecename = name                          # when there is an instance of the class.
      @composername = composer
      @piecelength = duration
    end
  end
  dvorakbmin = Piece.new("Cello Concerto in B minor [Finale]", "Dvorak", "13:00")
  print "instance dvorakbin being printed out: "
  puts dvorakbmin
  print "Call to to_s method of dvorakbmin instance: "
  dvorakbmin.to_s
  print "\n"
  class Piece                                   # ^ Extend the existing Piece class. ^
    def to_s                                    # Define the to_s method to print out the parameters.
      print "Your piece: #{@composername}'s #{@piecename} lasts #{@piecelength}."
    end
  end
  puts "This is the instance of the class Piece: "
  elgaremin = Piece.new("Cello Concerto in E minor mvt I", "Edward Elgar", "7:22")
  puts "This is the instance being put out."
  puts elgaremin
  puts "This is the call to the to_s method in Piece."
  elgaremin.to_s
  print "\n\n"
  print "Now defined will be the subclass 'MusicMinusOne' of the superclass 'Piece'.\n"
  class MusicMinusOne < Piece
    def initialize (name, composer, duration, instrument)
      super(name, composer, duration)
      @minusone = instrument
    end
  end
  print "This should display the name, composer, and duration of the MMO Dvorak, but without the subclass's @minusone instance variable: \n"
  dvorakMMO = MusicMinusOne.new("'Cello Concerto in B minor [Finale]", "Dvorak", "13:00", "violoncello")
  dvorakMMO.to_s
  class MusicMinusOne < Piece
    def to_s
      print super + "  The #{@minusone} instrumentalist will be accompanied by an orchestra."
    end
  end
  puts "\nNow displayed will be the newest version of our to_s method: "
  dvorakMMO.to_s
  print "\n"

Your Piece: Dvorak's 'Cello Concerto in B minor [Finale] lasts 13:00.C:/Documents and Settings/Josh Hanson/Desktop/Programming/Ruby/test1.rb:91:in 'to_s': undefined method '+' for nil:NilClass (NoMethodError) from C:/Documents and Settings/Josh Hanson/Desktop/Programming/Ruby/test1.rb:95

puts my_instance

print my_instance.to_s
print "\n"

class Piece                                 
        def initialize (name, composer, duration) 
                @piecename = name                         
                @composername = composer
                @piecelength = duration
        end
end

dvorakbmin = Piece.new("Cello Concerto in B minor [Finale]", "Dvorak", "13:00")

print "instance dvorakbin being printed out: "
puts dvorakbmin

print "Call to to_s method of dvorakbmin instance: "
puts dvorakbmin

class Piece                               
        def to_s                                   
                "Your piece: #{@composername}'s #{@piecename} lasts #{@piecelength}."
        end
end

elgaremin = Piece.new("Cello Concerto in E minor mvt I", "Edward Elgar", "7:22")

puts "This is the instance of the class Piece: "
puts "This is the instance being put out."
puts elgaremin

puts "This is the call to the to_s method in Piece."
puts elgaremin
puts

puts "Now defined will be the subclass 'MusicMinusOne' of the superclass 'Piece'."

class MusicMinusOne < Piece
        def initialize (name, composer, duration, instrument)
                super(name, composer, duration)
                @minusone = instrument
        end
end

puts "This should display the name, composer, and duration of the MMO Dvorak, but without the subclass's @minusone instance variable:"

dvorakMMO = MusicMinusOne.new("'Cello Concerto in B minor [Finale]", "Dvorak", "13:00", "violoncello")
puts dvorakMMO

class MusicMinusOne
        def to_s
                super + "  The #{@minusone} instrumentalist will be accompanied by an orchestra."
        end
end

puts "Now displayed will be the newest version of our to_s method: "
puts dvorakMMO