diff --git a/lumps/genmidi/dumpgenmidi b/lumps/genmidi/dumpgenmidi
index add554c0..1cddb4c1 100644
--- a/lumps/genmidi/dumpgenmidi
+++ b/lumps/genmidi/dumpgenmidi
@@ -26,23 +26,41 @@ def instr_to_str_def(filename, filename2, instr):
     if is_null_voice(instr.voice1):
         return "NullInstrument"
 
-    args = ['"%s"' % filename]
+    file_args = "%r" % filename
 
     if instr.voice2 is not None:
-        args.append('"%s"' % filename2)
+        file_args += ", %r" % filename2
 
+    instr_name = instr.voice1["name"]
+
+    extra_args = []
     if instr.fixed_note is not None:
-        args.append("note=%s" % midi.def_for_note(instr.fixed_note))
+        extra_args.append("note=%s" % midi.def_for_note(instr.fixed_note))
     if instr.offset1 != 0:
-        args.append("off1=%i" % instr.offset1)
+        extra_args.append("off1=%+i" % instr.offset1)
     if instr.offset2 != 0:
-        args.append("off2=%i" % instr.offset2)
+        extra_args.append("off2=%+i" % instr.offset2)
+    if instr.tune != 0:
+        extra_args.append("tune=%+i" % instr.tune)
 
-    return "Instrument(%s)" % (", ".join(args))
+    extra_args = ", ".join(extra_args)
+    if extra_args:
+        file_args += ", "
+
+    if len(file_args + extra_args) <= 32:
+        return "\tInstrument(%s%s), %s# %s" % (
+            file_args, extra_args,
+            " " * (32 - len(file_args + extra_args)),
+            instr_name)
+
+    return "\tInstrument(%s %s# %s\n\t           %s)," % (
+        file_args.strip(),
+         " " * (35 - len(file_args)), instr_name,
+         extra_args)
 
 
 def print_instr_def(filename, filename2, instr):
-    print("\t%s," % instr_to_str_def(filename, filename2, instr))
+    print(instr_to_str_def(filename, filename2, instr))
 
 
 def dump_instrument(filename, filename2, instr):
@@ -65,6 +83,9 @@ instruments = genmidi.read(sys.argv[1])
 main_instrs = instruments[0:128]
 percussion = instruments[128:]
 
+print("# Note: all instruments must ALWAYS be defined, or use NullInstrument.")
+print("")
+print("# General MIDI instruments:")
 print("INSTRUMENTS = [")
 
 for i in range(len(main_instrs)):
@@ -76,6 +97,7 @@ for i in range(len(main_instrs)):
 
 print("]")
 print("")
+print("# Percussion instruments:")
 print("PERCUSSION = [")
 
 for i in range(len(percussion)):