error.txt

What it the artist name ?:>1
What is the song name ?:>2
library.rb:32:in `add_song': undefined method `<<' for nil:NilClass (NoMethodError)
	from library.rb:59:in `<main>'

library.rb

module Menu
	puts "Hello ! This is an amazing app for organizing your music ! This is a
	cool library ! It allows you to do multiple tasks
	What would you like to do ? 
	-- 1 add a music ? 
	-- 2 delete a music ?
	-- 3 delete an album ?
	"
end

module Promptable
	def prompt(message = "What music would you like to add", symbol = ":>")
	print message
	print symbol
	gets.chomp
	end
end


class Library
	attr_accessor :artist, :song

	def initialize
		@library = {}
	end

	def add_artist(artist)
		@library[artist] = []
	end

	def add_song(song)
		@library[artist] << song
	end

	def show
		puts @library
	end
end

class Artist
	attr_accessor :name, :song
	def initialize(artist)
		@name = artist[:name]
		@song = artist[:song]

	end

	def to_s
	 "#{name}, #{song}"
	end
end


 if __FILE__ == $PROGRAM_NAME
 	include Promptable
 	include Menu
	my_library = Library.new
	my_library.add_artist(Artist.new(:name => prompt("What it the artist name ?")))
	my_library.add_song(Artist.new(:song => prompt("What is the song name ?")))
	my_library.show
end