diff --git a/Keybinding.Test/ChordCultureInvarianceTests.cs b/Keybinding.Test/ChordCultureInvarianceTests.cs
new file mode 100644
index 0000000..1473e2c
--- /dev/null
+++ b/Keybinding.Test/ChordCultureInvarianceTests.cs
@@ -0,0 +1,67 @@
+// Copyright (c) 2023-2026 ktsu-dev contributors
+
+namespace ktsu.Keybinding.Test;
+
+using System.Globalization;
+using ktsu.Keybinding.Core.Models;
+
+[TestClass]
+[DoNotParallelize]
+public class ChordCultureInvarianceTests
+{
+	// et-EE sorts Z before T, and lt-LT sorts Y before J, so a culture-sensitive sort orders these pairs
+	// differently from en-US.
+	[TestMethod]
+	[DataRow("Ctrl+T+Z", "et-EE")]
+	[DataRow("Ctrl+J+Y", "lt-LT")]
+	public void HashCodeAndSetLookupDoNotDependOnTheThreadCulture(string text, string otherCulture)
+	{
+		CultureInfo original = CultureInfo.CurrentCulture;
+		try
+		{
+			CultureInfo.CurrentCulture = new CultureInfo("en-US");
+			Chord chord = Chord.Parse(text);
+			HashSet<Chord> set = [chord];
+			Dictionary<Chord, string> map = new() { [chord] = "handler" };
+			int hash = chord.GetHashCode();
+
+			CultureInfo.CurrentCulture = new CultureInfo(otherCulture);
+			Chord reparsed = Chord.Parse(text);
+
+			Assert.AreEqual(hash, chord.GetHashCode());
+			Assert.AreEqual(hash, reparsed.GetHashCode());
+			Assert.IsTrue(set.Contains(chord));
+			Assert.IsTrue(set.Contains(reparsed));
+			Assert.IsTrue(map.TryGetValue(reparsed, out string? handler));
+			Assert.AreEqual("handler", handler);
+		}
+		finally
+		{
+			CultureInfo.CurrentCulture = original;
+		}
+	}
+
+	[TestMethod]
+	[DataRow("Ctrl+T+Z", "et-EE")]
+	[DataRow("Ctrl+J+Y", "lt-LT")]
+	public void StoredNoteOrderDoesNotDependOnTheThreadCulture(string text, string otherCulture)
+	{
+		CultureInfo original = CultureInfo.CurrentCulture;
+		try
+		{
+			CultureInfo.CurrentCulture = new CultureInfo("en-US");
+			Chord english = Chord.Parse(text);
+
+			CultureInfo.CurrentCulture = new CultureInfo(otherCulture);
+			Chord other = Chord.Parse(text);
+
+			CollectionAssert.AreEqual(english.Notes.ToList(), other.Notes.ToList());
+			Assert.AreEqual(english.ToString(), other.ToString());
+			Assert.AreEqual(text, other.ToString());
+		}
+		finally
+		{
+			CultureInfo.CurrentCulture = original;
+		}
+	}
+}
diff --git a/Keybinding.Test/Keybinding.Test.csproj b/Keybinding.Test/Keybinding.Test.csproj
index 439c95d..7a6b91f 100644
--- a/Keybinding.Test/Keybinding.Test.csproj
+++ b/Keybinding.Test/Keybinding.Test.csproj
@@ -6,6 +6,8 @@
     <IsTestProject>true</IsTestProject>
     <TargetFramework>net10.0</TargetFramework>
     <TargetFrameworks></TargetFrameworks>
+    <!-- Culture tests need real culture data; in invariant mode every culture sorts like the invariant one. -->
+    <InvariantGlobalization>false</InvariantGlobalization>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Keybinding.Test/ModifierAliasNormalizationTests.cs b/Keybinding.Test/ModifierAliasNormalizationTests.cs
index 449fd09..4c01dbc 100644
--- a/Keybinding.Test/ModifierAliasNormalizationTests.cs
+++ b/Keybinding.Test/ModifierAliasNormalizationTests.cs
@@ -43,6 +43,7 @@ private static KeybindingService CreateService()
 	[DataRow("Windows", "Meta")]
 	[DataRow("Cmd", "Meta")]
 	[DataRow("Command", "Meta")]
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Globalization", "CA1308:Normalize strings to uppercase", Justification = "The test feeds a lowercase alias on purpose.")]
 	public void EveryConstructionPath_NormalizesModifierAliases(string alias, string canonical)
 	{
 		ArgumentNullException.ThrowIfNull(alias);
diff --git a/Keybinding/Models/MusicalTypes.cs b/Keybinding/Models/MusicalTypes.cs
index acbe933..48a027d 100644
--- a/Keybinding/Models/MusicalTypes.cs
+++ b/Keybinding/Models/MusicalTypes.cs
@@ -194,7 +194,9 @@ public Chord(IEnumerable<Note> notes)
 			throw new ArgumentException("Chord cannot contain a null note", nameof(notes));
 		}
 
-		_notes = [.. given.Distinct().OrderBy(n => n.Key.ToString())];
+		// Ordinal, so the stored order (which ToString, the saved file and GetHashCode rely on) is the same
+		// whatever the culture of the thread that built the chord.
+		_notes = [.. given.Distinct().OrderBy(n => n.Key.ToString(), StringComparer.Ordinal)];
 
 		if (_notes.Count == 0)
 		{
@@ -320,8 +322,9 @@ other is not null &&
 	/// <inheritdoc/>
 	public override int GetHashCode()
 	{
+		// _notes is already in ordinal order, so equal chords hash their notes in the same order on any thread.
 		HashCode hashCode = new();
-		foreach (Note note in _notes.OrderBy(n => n.Key.ToString()))
+		foreach (Note note in _notes)
 		{
 			hashCode.Add(note);
 		}