duplicate_tracks.rb

require 'rubygems'
require 'rbosa'

OSA.utf8_strings = true

itunes = OSA.app('iTunes')
library = itunes.sources.find {|s| s.kind == OSA::ITunes::ESRC::LIBRARY }

tracks = {}

library.playlists[0].tracks.sort_by {|t| t.rating }.reverse.each do |track|
  key = [
    track.artist,
    track.name,
    #track.album,
    track.duration.to_i.to_s
  ].join("\t").downcase

  if tracks[key]
    track.rating = 20
  end
  tracks[key] = true
end