The -n argument gives the number of albums to list; Library.txt is 
the input playlist.  The output columns are: genre; number of plays 
for unrated tracks; album name.

mark$ ./unrated_albums.pl -n 10 Library.txt
      Classical  117 Britten: A Ceremony Of Carols (B Britten)
      Classical  109 The Complete Keyboard Works of J. S. Bach Vol. 5: The Two And Three Part Inventions (Joao Carlos Martins)
      Classical  107 Handel - Recorder Sonatas (Marion Verbruggen)
      Classical  104 Mussorgsky (Ravel): Bilder einer Ausstellung - Stravinsky: Le Sacre du Printemps (Berliner Philharmoniker Herbert von Karajan)
      Classical  104 Handel: Concerti Grossi - Oboe Concerti (G.F. Handel)
      Classical  100 Orff: Carmina Burana - San Francisco Symphony - Blomstedt (C. Orff)
           Jazz   93 The Complete Hot Five And Hot Seven Recordings (Disc 3) (Louis Armstrong)
      Classical   93 Bach - Goldberg Variations BWV 988 (Glenn Gould)
           Jazz   91 Early Ellington (Disk 3) (Duke Ellington)
           Jazz   87 The Legendary Dial Masters, Vol. 2 (Charlie Parker)