diff --git a/VERSION b/VERSION
index 4b29c29..f17a1b2 100644
--- a/VERSION
+++ b/VERSION
@@ -1,2 +1,2 @@
-December 30 2022
+January 05 2022
 
diff --git a/doc/CHANGES b/doc/CHANGES
index 408ee96..561a2cd 100644
--- a/doc/CHANGES
+++ b/doc/CHANGES
@@ -14976,3 +14976,22 @@ if (casecmp(word,"instrument") == 0 {
 in parsesound() (parseabc.c) was rewritten.
 
 
+January 05 2023
+
+abc2midi: instrument =F/D transposes cdec up by 3 semitones instead of
+down by 10 semitones in the following example.
+
+X:5
+T: wrong octave
+M: 4/4
+K:C
+V:1 instrument=F/D
+cdec z4
+V:2
+z4 c4
+
+Fix: Hudson Lacerda supplied me with pseudo-code (doc/hudsonshift.txt)
+which describes how all the transpose directives should work.
+This code was implemented in parseSoundScore() which now replaces
+parseSound(). It also fixes yaps.
+
diff --git a/doc/hudsonshift.txt b/doc/hudsonshift.txt
new file mode 100755
index 0000000..247760f
--- /dev/null
+++ b/doc/hudsonshift.txt
@@ -0,0 +1,57 @@
+init:
+  transp_sound =  transp_score = 0;
+
+ABC2MIDI: use transp_sound;
+YAPS: use transp_score;
+ABC2ABC: ignore and replicate instructions to output;
+
+
+/******************************************/
+
+if (p1==0) error();
+
+
+  sound:
+    if (p2==0)
+      error();
+    transp_sound = p2-p1;
+/*
+ sound=<note1><note2> transposes the playback according to the
+ specified interval (the typeset score is not affected)
+*/
+
+
+  score:
+    if (p2==0)
+      p2 = ( 72 );
+    transp_score = p2-p1;
+/*
+ score=<note1><note2> transposes the typeset score according to the
+ specified interval (the playback is not affected); if the second note
+ is omitted it is assumed to be a c (see writing abc code for
+ transposing instruments)
+*/
+
+
+  instrument:
+    if (p2==0)
+      p2 = p1;
+    transp_score = p2-p1;
+    transp_sound = p2-( 72 );
+/*
+ instrument=<note1>/<note2> is defined as score=<note1><note2> sound=c<note2>
+*/
+
+
+  shift:
+    if (p2==0)
+      error();
+    transp_score = transp_sound = p2-p1;
+/*
+ shift=<note1><note2> transposes the typeset score and the playback
+ according to the specified interval
+*/
+
+
+/******************************************/
+
diff --git a/parseabc.c b/parseabc.c
index 58c4558..f6d18b4 100644
--- a/parseabc.c
+++ b/parseabc.c
@@ -942,7 +942,7 @@ int interpret_voice_label (char *s, int num, int *is_new)
 }
 
 /* The following four functions parseclefs, parsetranspose,
- * parsesound, parseoctave are used to parse the K: field which not
+ * parseSoundScore, parseoctave are used to parse the K: field which not
  * only specifies the key signature but also other descriptors
  * used for producing a midi file or postscript file.
  *
@@ -1021,6 +1021,97 @@ parsetranspose (s, word, gottranspose, transpose)
   return 1;
 };
 
+int parseSoundScore (char **s,
+		     char *word,
+		     int *gottranspose,
+		     int *transpose)
+/* parses sound, score, instrument, and shift
+ * according to Hudson Lacerda's pseudo code file
+ * doc/hudsonshift.txt.
+ */
+{
+int p1,p2;
+int transp_sound;
+int transp_score;
+
+transp_sound = 0;
+transp_score = 0;
+
+if (casecmp(word,"sound") != 0
+ && casecmp(word,"shift") != 0
+ && casecmp(word,"instrument") != 0
+ && casecmp(word,"score") != 0
+  )
+  return 0;
+
+skipspace (s);
+if (**s != '=')
+    {
+      event_error ("expecting  '=' after sound, score, instrument or shift");
+     return 0;
+     } else {
+      *s = *s + 1;
+      skipspace (s);
+      p1 = note2midi (s,word);
+      p2 = note2midi (s,word);
+      if (p1 == 0) {
+	      event_error ("<note1> missing. cannot do anything");
+              }
+      /* p2 = 0 implies that <note2> is not given */
+
+     if (casecmp(word,"sound") == 0) {
+         if (p2 == 0) event_error("sound = requires <note2>");
+	 transp_sound = p2-p1;
+	 /*
+          sound=<note1><note2> transposes the playback according to the
+          specified interval (the typeset score is not affected)
+         */
+	 }
+
+      if (casecmp(word,"score") == 0) {
+         if (p2 == 0) p2 = 72;
+         transp_score = p2 - p1;
+	 /*
+          score=<note1><note2> transposes the typeset score according to the
+          specified interval (the playback is not affected); if the second note
+          is omitted it is assumed to be a c (see writing abc code for
+          transposing instruments)
+         */
+	 }
+
+      if (casecmp(word,"instrument") == 0) {
+         if (p2 == 0) p2 = p1;
+         transp_score = p2 - p1;
+	 transp_sound = p2 - 72;
+
+	 /*
+          instrument=<note1>/<note2> is defined as
+	  score=<note1><note2> sound=c<note2>
+         */
+      }
+
+      if (casecmp(word,"shift") == 0) {
+         if (p2 == 0) event_error("shift = requires <note2>");
+         transp_score = p2 - p1;
+	 transp_sound = p2 - p1;
+	 /*
+         shift=<note1><note2> transposes the typeset score and the playback
+         according to the specified interval
+         */
+         }
+
+      *gottranspose = 1;
+
+      if (fileprogram == ABC2MIDI) *transpose = transp_sound;
+      if (fileprogram == YAPS) *transpose = transp_score;
+      return(1);
+     }
+}
+
+
+
+
+/* parsesound has been replaced with parseSoundScore */
 /* [SS] 2021-10-11 */
 int parsesound (s, word, gottranspose, transpose)
 /* parses string sound = 
@@ -1049,9 +1140,9 @@ int parsesound (s, word, gottranspose, transpose)
       *s = *s + 1;
       skipspace (s);
       p1 = note2midi (s,word);
-      /*printf("p1 midi note = %d\n",p1);*/ 
+      printf("p1 midi note = %d\n",p1); 
       p2 = note2midi (s,word);
-      /*printf("p2 midi note = %d\n",p2);*/ 
+      printf("p2 midi note = %d\n",p2); 
 
       if (p2 == p1 || p2 == 0) {
           *transpose = 72 - p1;  /* [SS] 2022.12.30 */
@@ -1071,7 +1162,7 @@ int parsesound (s, word, gottranspose, transpose)
           *transpose = p2 - p1; /* [SS] 2022.02.18 2022.04.27 */
        }
        *gottranspose = 1;
-       /*printf("p1 = %d p2 = %d transpose = %d\n",p1,p2,*transpose);*/
+       printf("p1 = %d p2 = %d transpose = %d\n",p1,p2,*transpose);
      }
   return 1;
   }
@@ -1421,7 +1512,7 @@ parsekey (str)
 	parsed = parseoctave (&s, word, &gotoctave, &octave);
 
       if (!parsed)
-        parsed = parsesound (&s, word, &gottranspose, &transpose);
+        parsed = parseSoundScore (&s, word, &gottranspose, &transpose);
 
       if ((parsed == 0) && (casecmp (word, "Hp") == 0))
 	{
@@ -1668,7 +1759,7 @@ parsevoice (s)
       if (!parsed)
         parsed = parseoctave (&s, word, &vparams.gotoctave, &vparams.octave);
       if (!parsed)
-        parsed = parsesound (&s, word, &vparams.gottranspose, &vparams.transpose);
+        parsed = parseSoundScore (&s, word, &vparams.gottranspose, &vparams.transpose);
       /* Code changed JA 20 May 2022 */
       if ((!parsed) && (strcasecmp (word, "name") == 0)) {
         parsed =
diff --git a/store.c b/store.c
index ef3aab3..afdc0c2 100644
--- a/store.c
+++ b/store.c
@@ -186,7 +186,7 @@ int main()
 
 */
 
-#define VERSION "4.80 December 30 2022 abc2midi" 
+#define VERSION "4.81 January 05 2023 abc2midi" 
 
 /* enables reading V: indication in header */
 #define XTEN1 1
diff --git a/yapstree.c b/yapstree.c
index 9ea6a3e..5ab20e5 100644
--- a/yapstree.c
+++ b/yapstree.c
@@ -22,7 +22,7 @@
 /* yapstree.c - back-end for abc parser. */
 /* generates a data structure suitable for typeset music */
 
-#define VERSION "1.90 June 14 2022 yaps"
+#define VERSION "1.91 January 05 2023 yaps"
 #include <stdio.h>
 #ifdef USE_INDEX
 #define strchr index