* deal with duplicate instrument/parts better than failing

ruby/lib/jam_ruby/jam_track_importer.rb

@@ -774,6 +774,36 @@ module JamRuby
       instrument_weight
     end
 
+    def deduplicate_parts(tracks)
+      unique_instruments = {}
+
+      tracks.each do |track|
+
+        found = unique_instruments[[track.instrument_id, track.part]]
+        if !found
+          found = []
+        end
+
+        found << track
+      end
+
+      unique_instruments.each do |key, value|
+        if value.length > 1
+          count = 0
+
+          value.each do |track|
+            if track.part.nil?
+              track.part = (count + 1).to_s
+            else
+              track.part = "#{track.part} #{count + 1}"
+            end
+          end
+
+          count += 1
+        end
+      end
+    end
+
     def sort_tracks(tracks)
 
       sorted_tracks = tracks.sort do |a, b|
@@ -914,6 +944,8 @@ module JamRuby
       @@log.info("sorting tracks")
       tracks = sort_tracks(tracks)
 
+      deduplicate_parts(tracks)
+
       jam_track.jam_track_tracks = tracks
       jam_track.jam_track_files = addt_files