Done

lib/appointment.rb

@@ -0,0 +1,16 @@
+class Appointment
+    attr_accessor :date, :patient, :doctor
+
+    @@all = []
+
+    def initialize(date, patient, doctor)
+        @date = date
+        @patient = patient
+        @doctor = doctor
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+end

lib/artist.rb

@@ -0,0 +1,26 @@
+class Artist
+    attr_accessor :name
+
+    @@all = []
+
+    def initialize(name)
+        @name = name
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+
+    def songs
+        Song.all.select{|song| song.artist == self}
+    end
+
+    def new_song(name, genre)
+        Song.new(name, self, genre)
+    end
+
+    def genres
+        songs.map{|song| song.genre}
+    end
+end

lib/doctor.rb

@@ -0,0 +1,27 @@
+require 'pry'
+class Doctor
+    attr_accessor :name
+
+    @@all = []
+
+    def initialize(name)
+        @name = name
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+
+    def appointments
+        Appointment.all.select{|a| a.doctor == self}
+    end
+
+    def new_appointment(date, patient)
+        Appointment.new(date, patient, self)
+    end
+
+    def patients
+        self.appointments.map{|a| a.patient}
+    end
+end

lib/genre.rb

@@ -0,0 +1,22 @@
+class Genre
+    attr_accessor :name
+
+    @@all = []
+
+    def initialize(name)
+        @name = name
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+
+    def songs
+        Song.all.select{|song| song.genre == self}
+    end
+
+    def artists
+        self.songs.map{|song| song.artist}.uniq
+    end
+end

lib/patient.rb

@@ -0,0 +1,26 @@
+class Patient
+    attr_accessor :name
+
+    @@all = []
+
+    def initialize(name)
+        @name = name
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+
+    def appointments
+        Appointment.all.select{|a| a.patient == self}
+    end
+
+    def doctors
+        self.appointments.map{|a| a.doctor}
+    end
+
+    def new_appointment(date, doctor)
+        Appointment.new(date, self, doctor)
+    end
+end

lib/song.rb

@@ -0,0 +1,18 @@
+class Song
+    attr_accessor :title, :genre, :artist
+
+    @@all = []
+
+    def initialize(title, artist, genre)
+        @title = title
+        @artist = artist
+        @genre = genre
+        @@all << self
+    end
+
+    def self.all
+        @@all
+    end
+
+
+end