From fd70c644a298d05cf32883434b841e8549b8e031 Mon Sep 17 00:00:00 2001
From: Jacob Walls <jacobtylerwalls@gmail.com>
Date: Mon, 9 May 2022 13:06:10 -0400
Subject: [PATCH] Make cautionaryPitchClass=True work with chords

---
 music21/pitch.py        | 8 ++++++++
 music21/stream/base.py  | 3 ++-
 music21/stream/tests.py | 6 +++---
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/music21/pitch.py b/music21/pitch.py
index 250dc7235f..c23d38cd37 100644
--- a/music21/pitch.py
+++ b/music21/pitch.py
@@ -5039,6 +5039,14 @@ def set_displayStatus(newDisplayStatus: bool):
                       and cautionaryNotImmediateRepeat is False
                       and pPastInMeasure is False):
                     set_displayStatus(True)
+
+                # Avoid making early, incorrect assumptions if this pitch is part of a chord.
+                # pPast might include this note itself, in which case we should not say
+                # "natural already in past usage". (Filtering out the current note from pPast
+                # when calling this method is not sufficient, because there could be repetitions.)
+                elif (self._client is not None and self._client._chordAttached is not None):
+                    continue
+
                 # other cases: already natural in past usage, do not need
                 # natural again (and not in key sig)
                 else:
diff --git a/music21/stream/base.py b/music21/stream/base.py
index 961420a926..7e8d90544c 100644
--- a/music21/stream/base.py
+++ b/music21/stream/base.py
@@ -6368,6 +6368,7 @@ def makeAccidentals(
 
         Changed in v.6: does not return anything if inPlace is True.
         Changed in v.7: default inPlace is False
+        Changed in v.8: altered unisons in Chords now supply clarifying naturals.
 
         All arguments are keyword only.
         '''
@@ -6453,6 +6454,7 @@ def makeAccidentals(
                 # when reading a chord, this will apply an accidental
                 # if pitches in the chord suggest an accidental
                 seenPitchNames = set()
+                pitchPast += e.pitches
 
                 for n in list(e):
                     p = n.pitch
@@ -6478,7 +6480,6 @@ def makeAccidentals(
                 for pName in seenPitchNames:
                     tiePitchSet.add(pName)
 
-                pitchPast += e.pitches
             else:
                 tiePitchSet.clear()
 
diff --git a/music21/stream/tests.py b/music21/stream/tests.py
index 8066efae4b..0e220b71ca 100644
--- a/music21/stream/tests.py
+++ b/music21/stream/tests.py
@@ -2609,9 +2609,9 @@ def testMakeAccidentalsA(self):
         s.makeAccidentals(inPlace=True)
 
         self.assertTrue(n2.pitch.accidental.displayStatus)
-        # both a's in the chord now have naturals but are hidden
-        self.assertIsNone(c1.pitches[1].accidental)
-        # self.assertTrue(c1.pitches[2].accidental.displayStatus)
+        # Both A-naturals in the chord show accidentals
+        self.assertTrue(c1.pitches[1].accidental.displayStatus)
+        self.assertTrue(c1.pitches[2].accidental.displayStatus)
 
         # not getting a natural here because of chord tones
         # self.assertTrue(n3.pitch.accidental.displayStatus)