lib/sonos/system.rb
def party_mode new_master = nil
      return nil unless speakers.length > 1

      new_master = find_party_master if new_master.nil?

      party_over
      speakers.each do |slave|
        next if slave.uid == new_master.uid
        slave.join new_master
      end
      rescan @topology
    end
def party_mode new_master = nil
      return nil unless speakers.length > 1

      new_master = find_party_master if new_master.nil?

      party_over
      speakers.each do |slave|
        next if slave.uid == new_master.uid
        slave.join new_master
      end
      rescan @topology
    end
Party Mode!  Join all speakers into a single group.