gistfile1.rb

require 'eventmachine'

module Mplayer
  def receive_data(data)
  end
end

class Player
  def initialize
    @io = EM.popen("mplayer -noconsolecontrols -nolirc -idle -slave", Mplayer)
  end

  def play(track)
    @io.send_data("loadfile \"#{track}\" 0\n")
  end
end

EM.run do
  Player.new.play("/path/to/some/song.mp3")
end