music_example.rb

class Song
  attr_reader :name, :duration

  def initialize(name, duration)
    @name = name
    @duration = duration
  end

  def song
  end
end

class Album
  attr_reader :name, :release_year, :rating, :songs

  def initialize(name, release_year, rating, songs)
    @name = name
    @release_year = release_year
    @rating = rating
    @songs = songs
  end
end

class Artist
  attr_reader :name, :albums

  def initialize(name, albums)
    @name = name
    @albums = albums
  end

  def to_s
     output = "Artist Name: #{@name} has albums "
     @albums.each { |album| output << "#{album.name}, "}
     output
  end

  def include? album_name
    albums.each { |album| return true if album.name == album_name }
    false
  end
end

# Songs from animal
first_song = Song.new('Dinosaur', 120)
second_song = Song.new('Blah Blah Blah', 160)
third_song = Song.new('Take It Off', 200)

first_song.song

# Songs from cannibal
fourth_song = Song.new('Cannibal', 120)
fifth_song = Song.new('We R Who We R', 200)
sixth_song = Song.new('Grow A Pear', 140)

album_one_songs = [first_song, second_song, third_song]
album_two_songs = [fourth_song, fifth_song, sixth_song]

first_album = Album.new('Animal', 2010, 5, album_one_songs)
second_album = Album.new('Cannibal', 2010, 4, album_two_songs)

albums = [first_album, second_album]

artist = Artist.new('Kesha', albums)

artist.albums.each do |album|
  album.songs.each { |song| puts song.name }
end

puts artist.include? "Cannibal"
puts artist.include? "Warrior"