diff --git a/scripts/music-duplicates.py b/scripts/music-duplicates.py
index 5db55772..1afc79eb 100755
--- a/scripts/music-duplicates.py
+++ b/scripts/music-duplicates.py
@@ -4,6 +4,7 @@
 # that the project needs.
 
 from glob import glob
+import hashlib
 import os
 import re
 import sys
@@ -12,41 +13,22 @@ PHASE1_MATCH_RE = re.compile(r'(e\dm\d)', re.I)
 PHASE2_MATCH_RE = re.compile(r'(map\d\d)', re.I)
 FREEDM_MATCH_RE = re.compile(r'(dm\d\d)', re.I)
 
-DOOM2_TRACKS = (
-	'runnin', 'stalks', 'countd', 'betwee', 'doom', 'the_da', 'shawn',
-	'ddtblu', 'in_cit', 'dead', 'stlks2', 'theda2', 'doom2', 'ddtbl2',
-	'runni2', 'dead2', 'stlks3', 'romero', 'shawn2', 'messag', 'count2',
-	'ddtbl3', 'ampie', 'theda3', 'adrian', 'messg2', 'romer2', 'tense',
-	'shawn3', 'openin', 'evil', 'ultima',
-)
-
 def get_music_tracks():
-	"""Returns a dictionary mapping from MIDI name (subpath of musics/)
+	"""Returns a dictionary mapping from MIDI file SHA1
 	   to a list of game tracks that use that MIDI."""
 	result = {}
 	musics_path = os.path.join(os.path.dirname(sys.argv[0]), '../musics')
 	for mus in glob('%s/*.mus' % musics_path):
-		try:
-			symlink = os.readlink(mus)
-			if symlink not in result:
-				result[symlink] = []
-			result[symlink].append(os.path.basename(mus))
-		except OSError:
-			pass
+		with open(mus) as f:
+			contents = f.read()
+			m = hashlib.sha1()
+			m.update(contents)
+			digest = m.digest()
+			basename = os.path.basename(mus)
+			result.setdefault(digest, []).append(basename)
 	return result
 
-def doom2_level_for_file(filename):
-	"""Given a filename that may be named like a Doom 2 music name
-	   (eg. d_stalks.mid), get the level number it corresponds to
-	   or 0 if it doesn't match."""
-	filename = os.path.basename(filename)
-	for i, doom2_name in enumerate(DOOM2_TRACKS):
-		if filename.startswith('d_%s.' % doom2_name):
-			return i + 1
-	else:
-		return 0
-
-def get_prime_track(midi, tracks):
+def get_prime_track(tracks):
 	"""Given a list of tracks that all use the same MIDI, find the
 	   "prime" one (the one that isn't a reuse/duplicate)."""
 	# We have almost all Phase 2 tracks fulfilled. So if the same
@@ -56,25 +38,15 @@ def get_prime_track(midi, tracks):
 	if len(phase2_tracks) == 1:
 		return phase2_tracks[0]
 
-	level = doom2_level_for_file(midi)
-	if level:
-		for track in phase2_tracks:
-			if ('map%02i' % level) in track:
-				return track
-
-	# If the filename of the MIDI file (symlink target) describes a
-	# level, then that level is the leader.
-	m = PHASE1_MATCH_RE.search(os.path.basename(midi))
-	if m:
-		level = m.group(1)
-		for track in tracks:
-			if level in track:
-				return track
+	# FreeDM music has been hand-picked. So if it is used for both
+	# Phase 1 and FreeDM, assume it's probably a FreeDM track.
+	freedm_tracks = [x for x in tracks if FREEDM_MATCH_RE.search(x)]
+	if len(freedm_tracks) == 1:
+		return freedm_tracks[0]
 
 	# We're out of options. Pick the first one in the list.
-	#print 'Warning: Don't know which of %s is the leader for %s.' % (
-	#	tracks, midi)
-	return tracks[0]
+	#print "Warning: Don't know which of %s is the leader." % tracks
+	return sorted(tracks)[0]
 
 def find_missing_tracks(tracks):
 	"""Given a dictionary of tracks, get a list of "missing" tracks."""
@@ -82,7 +54,7 @@ def find_missing_tracks(tracks):
 	for midi, tracks in tracks.items():
 		if len(tracks) < 2:
 			continue
-		prime_track = get_prime_track(midi, tracks)
+		prime_track = get_prime_track(tracks)
 		result.extend(x for x in tracks if x != prime_track)
 	return result