--- vorbistagedit.orig	2008-11-28 09:06:04.051540085 +0100
+++ vorbistagedit	2008-11-28 09:50:24.763542228 +0100
@@ -68,6 +68,9 @@
 #
 # We are in directory:
 #  $(pwd)
+#
+# Tags that should be applied to all files can be specified
+# before the first per-file tag definiton starts.
 
 _eof
 
@@ -127,7 +130,8 @@
 write_tags() {
   echo -n "I:   processing $file... " >&2
   local file="$1"; shift
-  for tag; do echo "$tag"; done | vorbiscomment -w "$file"
+  for tag; do [ -n "${tag:-}" ] && echo "$tag"; done | \
+    vorbiscomment -w "$file"
   if [ -n "${filename_new:-}" ] && [ "${filename_new:-}" != "$file" ]; then
     echo; echo -n "I:     renaming to $filename_new... " >&2
     mv "$file" "$filename_new"
@@ -136,17 +140,18 @@
 }
 
 filename_new=
+global_tags=
 
 while read line; do
   case "$line" in
     ': EOF')
-      write_tags "$file" "$tags"
+      write_tags "$file" "$global_tags" "$tags"
       echo "done." >&2
       ;;
 
     :*)
       if [ -n "${file:-}" ]; then
-        write_tags "$file" "$tags"
+        write_tags "$file" "$global_tags" "$tags"
         echo "done." >&2
         tags=''
       fi
@@ -157,8 +162,14 @@
       filename_new="${line#* }";;
 
     *=*)
-      tags="${tags:+$tags
-}$line";;
+      if [ -z "${file:-}" ]; then  # global scope
+        global_tags="${global_tags:+$global_tags
+}$line"
+      else                         # file scope
+        tags="${tags:+$tags
+}$line"
+      fi
+      ;;
 
     *|'#*') :;;
   esac