# UNDF: UNDF-2026-000001127
--- a/src/engraving/rw/read400/read400.cpp
+++ b/src/engraving/rw/read400/read400.cpp
@@ -331,7 +331,7 @@ bool Read400::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
     Score* score = dst->score();
     ReadContext ctx(score);
     ctx.setPasteMode(true);

-    std::vector<Harmony*> pastedHarmony;
+    std::unordered_set<Harmony*> pastedHarmony;
     std::vector<Chord*> graceNotes;

@@ -625,7 +625,7 @@ bool Read400::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
                     // remove pre-existing chords on this track
                     // but be sure not to remove any we just added
                     for (EngravingItem* el : seg->findAnnotations(ElementType::HARMONY, ctx.track(), ctx.track())) {
-                        if (std::find(pastedHarmony.begin(), pastedHarmony.end(), el) == pastedHarmony.end()) {
+                        if (pastedHarmony.find(static_cast<Harmony*>(el)) == pastedHarmony.end()) {
                             score->undoRemoveElement(el);
                         }
                     }
                     harmony->setParent(seg);
                     score->undoAddElement(harmony);
-                    pastedHarmony.push_back(harmony);
+                    pastedHarmony.insert(harmony);
--- a/src/engraving/rw/read410/read410.cpp
+++ b/src/engraving/rw/read410/read410.cpp
@@ -331,7 +331,7 @@ bool Read410::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
     Score* score = dst->score();
     ReadContext ctx(score);
     ctx.setPasteMode(true);

-    std::vector<Harmony*> pastedHarmony;
+    std::unordered_set<Harmony*> pastedHarmony;
     std::vector<Chord*> graceNotes;

@@ -636,7 +636,7 @@ bool Read410::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
                     // remove pre-existing chords on this track
                     // but be sure not to remove any we just added
                     for (EngravingItem* el : seg->findAnnotations(ElementType::HARMONY, ctx.track(), ctx.track())) {
-                        if (std::find(pastedHarmony.begin(), pastedHarmony.end(), el) == pastedHarmony.end()) {
+                        if (pastedHarmony.find(static_cast<Harmony*>(el)) == pastedHarmony.end()) {
                             score->undoRemoveElement(el);
                         }
                     }
                     harmony->setParent(seg);
                     score->undoAddElement(harmony);
-                    pastedHarmony.push_back(harmony);
+                    pastedHarmony.insert(harmony);
--- a/src/engraving/rw/read460/read460.cpp
+++ b/src/engraving/rw/read460/read460.cpp
@@ -331,7 +331,7 @@ bool Read460::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
     Score* score = dst->score();
     ReadContext ctx(score);
     ctx.setPasteMode(true);

-    std::vector<Harmony*> pastedHarmony;
+    std::unordered_set<Harmony*> pastedHarmony;
     std::vector<Chord*> graceNotes;

@@ -641,7 +641,7 @@ bool Read460::pasteStaff(XmlReader& e, Segment* dst, staff_idx_t dstStaff, Frac
                     // remove pre-existing chords on this track
                     // but be sure not to remove any we just added
                     for (EngravingItem* el : seg->findAnnotations(ElementType::HARMONY, ctx.track(), ctx.track())) {
-                        if (std::find(pastedHarmony.begin(), pastedHarmony.end(), el) == pastedHarmony.end()) {
+                        if (pastedHarmony.find(static_cast<Harmony*>(el)) == pastedHarmony.end()) {
                             score->undoRemoveElement(el);
                         }
                     }
                     harmony->setParent(seg);
                     score->undoAddElement(harmony);
-                    pastedHarmony.push_back(harmony);
+                    pastedHarmony.insert(harmony);